CUT GEODESY LAB

PUBLICATIONS

Authors:

ALLDanezisFotiouKakoullisMelillosMiltiadouNikolaidisPekriTheocharidisVacanas

Type:

ALLPaper in conference proceedingsJournal/magazine articleBook chapterPh.D. thesis

2022

• D. Kakoullis, K. Fotiou, G. Melillos, and C. Danezis. Considerations and Multi-Criteria Decision Analysis for the Installation of Collocated Permanent GNSS and SAR Infrastructures for Continuous Space-based Monitoring of Natural Hazards. Remote sensing, 14(4):1020, 2022. doi:10.3390/rs14041020
  [BibTeX] [Abstract] [Download PDF]
  

  Over the past few decades, the global population and the built environment’s vulnerability to natural hazards have risen dramatically. As a result, decisive actions, such as the SENDAI framework, have emerged to foster a global culture of successful disaster risk reduction policies, including actions to mitigate the social and economic impact of geohazards. The effective study of natural disasters requires meticulous and precise monitoring of their triggering factors, with ground- and space-based techniques. The integration of GNSS and SAR observations through the establishment of permanent infrastructures, i.e., Continuously Operating Reference Stations (CORS) networks and arrays of Corner Reflectors (CRs), may form a seamless ground displacement monitoring system. The current research literature provides fragmented guidelines, regarding the co-location of SAR and GNSS permanent infrastructures. Furthermore, there exist no guidelines for the determination of the most suitable locations using a holistic approach, in terms of criteria and required data. The purpose of this paper is to present a semi-automatic multicriteria site suitability analysis and evaluation of candidate sites for the installation of a permanent CORS and two CRs; one for each pass, taking into account various parameters and criteria. The first results demonstrate that the collocation of SAR and GNSS permanent infrastructures, utilizing a holistic criteria-based approach, is successful and complies with all the literature’s requirements.

  @Article{kakoullis_considerations_2022,
  author = {Kakoullis, D. and Fotiou, K. and Melillos, G. and Danezis, C.},
  title = {Considerations and {M}ulti-{C}riteria {D}ecision {A}nalysis for the {I}nstallation of {C}ollocated {P}ermanent {GNSS} and {SAR} {I}nfrastructures for {C}ontinuous {S}pace-based {M}onitoring of {N}atural {H}azards},
  journal = {Remote Sensing},
  volume = {14},
  month = feb,
  year = {2022},
  number = {4},
  article-number = {1020},
  URL = {https://www.mdpi.com/2072-4292/14/4/1020},
  ISSN = {2072-4292},
  abstract = {Over the past few decades, the global population and the built environment’s vulnerability to natural hazards have risen dramatically. As a result, decisive actions, such as the SENDAI framework, have emerged to foster a global culture of successful disaster risk reduction policies, including actions to mitigate the social and economic impact of geohazards. The effective study of natural disasters requires meticulous and precise monitoring of their triggering factors, with ground- and space-based techniques. The integration of GNSS and SAR observations through the establishment of permanent infrastructures, i.e., Continuously Operating Reference Stations (CORS) networks and arrays of Corner Reflectors (CRs), may form a seamless ground displacement monitoring system. The current research literature provides fragmented guidelines, regarding the co-location of SAR and GNSS permanent infrastructures. Furthermore, there exist no guidelines for the determination of the most suitable locations using a holistic approach, in terms of criteria and required data. The purpose of this paper is to present a semi-automatic multicriteria site suitability analysis and evaluation of candidate sites for the installation of a permanent CORS and two CRs; one for each pass, taking into account various parameters and criteria. The first results demonstrate that the collocation of SAR and GNSS permanent infrastructures, utilizing a holistic criteria-based approach, is successful and complies with all the literature’s requirements.},
  doi = {10.3390/rs14041020},
  pages = {1020}
  }

• K. Fotiou, D. Kakoullis, M. Pekri, G. Melillos, R. Brcic, M. Eineder, D. G. Hadjimitsis, and C. Danezis. Space-based Displacement Monitoring of Coastal Urban Areas: The Case of Limassol’s Coastal Front. Remote sensing, 14(4):914, feb 2022. doi:10.3390/rs14040914
  [BibTeX] [Abstract] [Download PDF]
  

  In the last five years, the urban development of the city of Limassol has rapidly increased in the sectors of industry, trade, real estate, and many others. This exponentially increased urban development arises several concerns about the aggravation of potential land subsidence in the Limassol coastal front. Forty six Copernicus Sentinel-1 acquisitions from 2017 to 2021 have been processed and analyzed using the Sentinel Application Platform (SNAP) and the Stanford Method for Persistent Scatterers (StaMPS). A case study for the identification and analysis of the persistent scatterers (PS) in pixels in a series of interferograms and the quantity of the land displacements in the line of sight of the Limassol coastal front is presented in this research, with subsidence rates up to about (−5 to 4 mm/year). For the validation of the detected deformation, accurate ground-based geodetic measurements along the coastal area were used. Concordantly, considering that there is a significant number of skyscrapers planned or currently under construction, this study attempts a preliminary assessment of the impact these structures will pose on the coastal front of the area of Limassol.

  @Article{fotiou_displacements_2022,
  author = {Fotiou, K. and Kakoullis, D. and Pekri, M. and Melillos, G. and Brcic, R. and Eineder, M. and Hadjimitsis, D. G. and Danezis, C.},
  title = {Space-based {D}isplacement {M}onitoring of {C}oastal {U}rban {A}reas: {T}he {C}ase of {L}imassol's {C}oastal {F}ront},
  journal = {Remote Sensing},
  volume = {14},
  month = feb,
  year = {2022},
  number = {4},
  article-number = {914},
  url = {https://www.mdpi.com/2072-4292/14/4/914},
  ISSN = {2072-4292},
  abstract = {In the last five years, the urban development of the city of Limassol has rapidly increased in the sectors of industry, trade, real estate, and many others. This exponentially increased urban development arises several concerns about the aggravation of potential land subsidence in the Limassol coastal front. Forty six Copernicus Sentinel-1 acquisitions from 2017 to 2021 have been processed and analyzed using the Sentinel Application Platform (SNAP) and the Stanford Method for Persistent Scatterers (StaMPS). A case study for the identification and analysis of the persistent scatterers (PS) in pixels in a series of interferograms and the quantity of the land displacements in the line of sight of the Limassol coastal front is presented in this research, with subsidence rates up to about (−5 to 4 mm/year). For the validation of the detected deformation, accurate ground-based geodetic measurements along the coastal area were used. Concordantly, considering that there is a significant number of skyscrapers planned or currently under construction, this study attempts a preliminary assessment of the impact these structures will pose on the coastal front of the area of Limassol.},
  doi = {10.3390/rs14040914},
  pages = {914}
  }

• V. Andronis, V. Karathanassi, V. Tsalapati, P. Kolokoussis, M. Miltiadou, and C. Danezis. Time Series Analysis of Landsat Data for Investigating the Relationship between Land Surface Temperature and Forest Changes in Paphos Forest, Cyprus. Remote sensing, 14(4):1010, 2022. doi:10.3390/rs14041010
  [BibTeX] [Abstract] [Download PDF]
  

  This study aims to investigate how alternations of the land surface temperature (LST) affects the normalized difference vegetation index (NDVI) in Paphos forest, Cyprus, using Landsat-5 and Landsat-8 imagery for the time periods 1993–2000 and 2013–2018, respectively. A total of 262 Landsat images were processed to compute the mean monthly NDVI and LST values and create a time series. Using the Cook’s distance, the effect of missing values in the analysis of the time series were examined. Results from the cross-correlation and cross-variograms, decomposition model, and the BFAST algorithm were compared to produce reliable conclusions on forest changes and satellite, meteorological, and environmental data were combined to interpret the changes that occurred inside the forest. The decomposition analysis showed a decrease of 2.7\% in the LST for the period 1993–2000 and an increase of 4.6\% in the LST during the period 2013–2018. The NDVI trend is negatively correlated to the LST trend for both time periods. An increase in the LST trend was identified in November 1998 as well as in the NDVI trend in October 1994 and May 2014 that was caused by favorable climatic conditions. An increase in the NDVI trend from May 2014 to December 2015 may be related to reduced pityocampa attacks. An abrupt decrease was detected in December 2015 that was probably caused by the locust invasion that occurred in the island earlier that year. A positive correlation appears for LST and NDVI variables for time lags 4, 5, 6, 7, and 8 months. Overall, it was shown that LST and NDVI analysis is very promising for identifying potential forest decline.

  @article{andronis_time_2022,
  title = {Time {Series} {Analysis} of {Landsat} {Data} for {Investigating} the {Relationship} between {Land} {Surface} {Temperature} and {Forest} {Changes} in {Paphos} {Forest}, {Cyprus}},
  volume = {14},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  issn = {2072-4292},
  url = {https://www.mdpi.com/2072-4292/14/4/1010},
  doi = {10.3390/rs14041010},
  abstract = {This study aims to investigate how alternations of the land surface temperature (LST) affects the normalized difference vegetation index (NDVI) in Paphos forest, Cyprus, using Landsat-5 and Landsat-8 imagery for the time periods 1993–2000 and 2013–2018, respectively. A total of 262 Landsat images were processed to compute the mean monthly NDVI and LST values and create a time series. Using the Cook’s distance, the effect of missing values in the analysis of the time series were examined. Results from the cross-correlation and cross-variograms, decomposition model, and the BFAST algorithm were compared to produce reliable conclusions on forest changes and satellite, meteorological, and environmental data were combined to interpret the changes that occurred inside the forest. The decomposition analysis showed a decrease of 2.7\% in the LST for the period 1993–2000 and an increase of 4.6\% in the LST during the period 2013–2018. The NDVI trend is negatively correlated to the LST trend for both time periods. An increase in the LST trend was identified in November 1998 as well as in the NDVI trend in October 1994 and May 2014 that was caused by favorable climatic conditions. An increase in the NDVI trend from May 2014 to December 2015 may be related to reduced pityocampa attacks. An abrupt decrease was detected in December 2015 that was probably caused by the locust invasion that occurred in the island earlier that year. A positive correlation appears for LST and NDVI variables for time lags 4, 5, 6, 7, and 8 months. Overall, it was shown that LST and NDVI analysis is very promising for identifying potential forest decline.},
  language = {en},
  number = {4},
  urldate = {2022-02-19},
  journal = {Remote Sensing},
  author = {Andronis, V. and Karathanassi, V. and Tsalapati, V. and Kolokoussis, P. and Miltiadou, M. and Danezis, C.},
  month = jan,
  year = {2022},
  keywords = {Big Earth Observation Data, breakpoints, cross-correlation, decomposition, Kalman filter, Landsat, LST, Mediterranean forest, NDVI, time series},
  pages = {1010},
  file = {Full Text PDF:/Users/chrisdanezis/Zotero/storage/UF55DKMW/Andronis et al. - 2022 - Time Series Analysis of Landsat Data for Investiga.pdf:application/pdf;Snapshot:/Users/chrisdanezis/Zotero/storage/K2MK8585/1010.html:text/html},
  }

2021

• M. Miltiadou, E. Antoniou, C. Theocharidis, and C. Danezis. Do People Understand and Observe the Effects of Climate Crisis on Forests? The Case Study of Cyprus. Forests, 12(9):1152, 2021. doi:10.3390/f12091152
  [BibTeX] [Abstract] [Download PDF]
  

  Recent reports stress the vulnerability of forest ecosystems in the European Union (EU), especially in the south. Cyprus is an island in the south of EU and the eastern of the Mediterranean Sea. While Cyprus’ vulnerability is stressed, Cyprus was included in the worst-performing countries regarding EU carbon emission’s targets of 2020. For mitigating climate change, Cyprus could benefit for tailored education and improved policy making. This study analyses the perceptions of the Cypriot residents about climate change and forest degradation aiming (1) to gain a better understanding of whether Cypriot residents understand its importance, (2) to understand if the general public is able to observe the changes noted in the literature, (3) to understand how perceptions are differentiated across different demographic categories, and (4) to derive correlations between demographic data and perceptions. This is a quantitative study; a questionnaire was used as a tool and the responses received were 416. It was highlighted that 65.62\% of the participants stated that they noticed moderate to very much degradation of Cypriot coniferous forests. A potential degradation reason was written down by 150 people, of whom 31.33\% referred to tree die-back, while many stated decreased soil moisture and difficulty in regeneration. All these reasons of degradation were either stated or suspected in the literature. Additionally, the demographic analysis showed that there may be an association between employability and beliefs/observations about climate change. The results of the research could be used for tailored education, further research, and promoting environmentally friendly policies. This will support Cyprus and other countries in reaching their Green Deal targets and, consequently, mitigate the severe effects of climate change.

  @article{miltiadou_people_2021,
  title = {Do {People} {Understand} and {Observe} the {Effects} of {Climate} {Crisis} on {Forests}? {The} {Case} {Study} of {Cyprus}},
  volume = {12},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  shorttitle = {Do {People} {Understand} and {Observe} the {Effects} of {Climate} {Crisis} on {Forests}?},
  url = {https://www.mdpi.com/1999-4907/12/9/1152},
  doi = {10.3390/f12091152},
  abstract = {Recent reports stress the vulnerability of forest ecosystems in the European Union (EU), especially in the south. Cyprus is an island in the south of EU and the eastern of the Mediterranean Sea. While Cyprus’ vulnerability is stressed, Cyprus was included in the worst-performing countries regarding EU carbon emission’s targets of 2020. For mitigating climate change, Cyprus could benefit for tailored education and improved policy making. This study analyses the perceptions of the Cypriot residents about climate change and forest degradation aiming (1) to gain a better understanding of whether Cypriot residents understand its importance, (2) to understand if the general public is able to observe the changes noted in the literature, (3) to understand how perceptions are differentiated across different demographic categories, and (4) to derive correlations between demographic data and perceptions. This is a quantitative study; a questionnaire was used as a tool and the responses received were 416. It was highlighted that 65.62\% of the participants stated that they noticed moderate to very much degradation of Cypriot coniferous forests. A potential degradation reason was written down by 150 people, of whom 31.33\% referred to tree die-back, while many stated decreased soil moisture and difficulty in regeneration. All these reasons of degradation were either stated or suspected in the literature. Additionally, the demographic analysis showed that there may be an association between employability and beliefs/observations about climate change. The results of the research could be used for tailored education, further research, and promoting environmentally friendly policies. This will support Cyprus and other countries in reaching their Green Deal targets and, consequently, mitigate the severe effects of climate change.},
  language = {en},
  number = {9},
  urldate = {2022-01-08},
  journal = {Forests},
  author = {Miltiadou, M. and Antoniou, E. and Theocharidis, C. and Danezis, C.},
  month = sep,
  year = {2021},
  publisher = {Multidisciplinary {Digital} {Publishing} {Institute}},
  keywords = {climate change, Cyprus, forests, Mediterranean, perceptions, questionnaire},
  pages = {1152},
  file = {Snapshot:/Users/chrisdanezis/Zotero/storage/PXRNTXQ5/1152.html:text/html;Full Text PDF:/Users/chrisdanezis/Zotero/storage/BNT2JUQZ/Miltiadou et al. - 2021 - Do People Understand and Observe the Effects of Cl.pdf:application/pdf},
  }

• K. Themistocleous, C. Danezis, and V. Gikas. Monitoring Ground Deformation of Cultural Heritage Sites using SAR and Geodetic Techniques: The Case Study of Choirokoitia, Cyprus. Applied geomatics, 13(1):37–49, feb 2021. doi:10.1007/s12518-020-00329-0
  [BibTeX] [Abstract] [Download PDF]
  

  Nowadays, assessing geo-hazards in cultural heritage sites in most cases takes place after the hazard has occurred. Monitoring structural and ground deformation resulting from geo-hazards facilitates the early recognition of potential risks and encourages effective conservation planning. This paper presents an integrated ground deformation monitoring approach based on the combined use of satellite SAR data, campaign-based GPS/GNSS observations, and aerial images from UAVs within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia is one of the most important prehistoric sites in the Eastern Mediterranean. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. As part of the PROTHEGO project, a series of field measurements were collected at the Choirokoitia site and compared against satellite SAR data to verify kinematic behavior of the broader area and to assist in monitoring potential geo-hazards over time. The results obtained indicate displacement rates of the order of 0.03 m/year. These results indicate that ground deformation should be monitored in the area surrounding the Choirokoitia using long-term, low-impact monitoring systems such as SAR images and UAV-based and geodetic techniques. The combination of such monitoring technologies can be compared to monitor and assess potential geo-hazards on archeological sites with increased accuracy.

  @article{themistocleous_monitoring_2021,
  title = {Monitoring {G}round {D}eformation of {C}ultural {H}eritage {S}ites using {SAR} and {G}eodetic {T}echniques: {T}he {C}ase {S}tudy of {Choirokoitia}, {Cyprus}},
  volume = {13},
  issn = {1866-928X},
  shorttitle = {Monitoring ground deformation of cultural heritage sites using {SAR} and geodetic techniques},
  url = {https://doi.org/10.1007/s12518-020-00329-0},
  doi = {10.1007/s12518-020-00329-0},
  abstract = {Nowadays, assessing geo-hazards in cultural heritage sites in most cases takes place after the hazard has occurred. Monitoring structural and ground deformation resulting from geo-hazards facilitates the early recognition of potential risks and encourages effective conservation planning. This paper presents an integrated ground deformation monitoring approach based on the combined use of satellite SAR data, campaign-based GPS/GNSS observations, and aerial images from UAVs within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia is one of the most important prehistoric sites in the Eastern Mediterranean. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. As part of the PROTHEGO project, a series of field measurements were collected at the Choirokoitia site and compared against satellite SAR data to verify kinematic behavior of the broader area and to assist in monitoring potential geo-hazards over time. The results obtained indicate displacement rates of the order of 0.03 m/year. These results indicate that ground deformation should be monitored in the area surrounding the Choirokoitia using long-term, low-impact monitoring systems such as SAR images and UAV-based and geodetic techniques. The combination of such monitoring technologies can be compared to monitor and assess potential geo-hazards on archeological sites with increased accuracy.},
  language = {en},
  number = {1},
  urldate = {2022-01-09},
  journal = {Applied Geomatics},
  author = {Themistocleous, K. and Danezis, C. and Gikas, V.},
  month = feb,
  year = {2021},
  pages = {37--49},
  file = {Springer Full Text PDF:/Users/chrisdanezis/Zotero/storage/ZRU4G3LM/Themistocleous et al. - 2021 - Monitoring ground deformation of cultural heritage.pdf:application/pdf},
  }

• F. Eliades, D. Hadjimitsis, and C. Danezis. Detecting Changes in Vegetation and Climate that Serve as Early Warning Signal on Land Degradation using Remote Sensing: a Review. In Remote sensing for agriculture, ecosystems, and hydrology xxiii, volume 11856, page 234–247. SPIE,, sep 2021.
  [BibTeX]

  @inproceedings{eliades2021detecting,
  title={Detecting {C}hanges in {V}egetation and {C}limate that {S}erve as {E}arly {W}arning {S}ignal on {L}and {D}egradation using {R}emote {S}ensing: a {R}eview},
  author={Eliades, F. and Hadjimitsis, D. and Danezis, C.},
  booktitle={Remote Sensing for Agriculture, Ecosystems, and Hydrology XXIII},
  volume={11856},
  pages={234--247},
  year={2021},
  month=sep,
  organization={SPIE}
  }

• C. Danezis, D. Kakoullis, K. Fotiou, M. Pekri, M. Chatzinikos, C. Kotsakis, R. Brcic, M. Eineder, M. Nikolaidis, G. Ioannou, A. Christofe, N. Kyriakides, G. Melillos, M. Christoforou, M. Tzouvaras, S. Pilidou, K. Themistocleous, and D. Hadjimitsis. CyCLOPS: a National Integrated GNSS/InSAR Strategic Research Infrastructure for Monitoring Geohazards and Forming the Next Generation Datum of the Republic of Cyprus. In Iag 2021: scientific assembly of the international association of geodesy. IAG,, 2021.
  [BibTeX]

  @inproceedings{danezis_iag_cyclops_2021,
  title={{CyCLOPS}: A {N}ational {I}ntegrated {GNSS/InSAR} {S}trategic {R}esearch {I}nfrastructure for {M}onitoring {G}eohazards and {F}orming the {N}ext {G}eneration {D}atum of the {R}epublic of {C}yprus},
  author={Danezis, C. and Kakoullis, D. and Fotiou, K. and Pekri, M. and Chatzinikos, M. and Kotsakis, C. and Brcic, R. and Eineder, M. and Nikolaidis, M. and Ioannou, G. and Christofe, A. and Kyriakides, N. and Melillos, G. and Christoforou, M. and Tzouvaras, M. and Pilidou, S. and Themistocleous, K. and Hadjimitsis, D.},
  booktitle={IAG 2021: Scientific Assembly of the International Association of Geodesy},
  year={2021},
  month=jun,
  organization={IAG}
  }

• C. Danezis, M. Chatzinikos, and C. Kotsakis. ITRF Densification in Cyprus. In Iag 2021: scientific assembly of the international association of geodesy. IAG,, jun 2021.
  [BibTeX]

  @inproceedings{danezis_iag_densification_2021,
  title={{ITRF} {D}ensification in {C}yprus},
  author={Danezis, C. and Chatzinikos, M. and Kotsakis, C.},
  booktitle={IAG 2021: Scientific Assembly of the International Association of Geodesy},
  year={2021},
  month=jun,
  organization={IAG}
  }

• M. Miltiadou, C. Theocharidis, V. Karathanassi, A. Agapiou, M. Nikolaidis, and C. Danezis. Understanding Phenological Changes of Coniferous Forests in Cyprus using Timeseries of SAR Data from 2015 till 2020. In Proceedings of the silvilaser conference 2021, page 145–147, 2021.
  [BibTeX]

  @inproceedings{miltiadou2021understanding,
  title={Understanding {P}henological {C}hanges of {C}oniferous {F}orests in {C}yprus using {T}imeseries of {SAR} {D}ata from 2015 till 2020},
  author={Miltiadou, M. and Theocharidis, C. and Karathanassi, V. and Agapiou, A. and Nikolaidis, M. and Danezis, C.},
  booktitle={Proceedings of the SilviLaser Conference 2021},
  pages={145--147},
  year={2021}
  }

• D. Kakoullis, K. Fotiou, G. Melillos, and C. Danezis. Considerations and Multi-Criteria Decision Analysis for the Installation of Permanent Infrastructures for Continuous Space-based Monitoring of Natural Hazards. In 40th earsel symposium. Earsel, jun 2021.
  [BibTeX]

  @inproceedings{kakoullis2021earsel,
  title = {Considerations and {M}ulti-{C}riteria {D}ecision {A}nalysis for the {I}nstallation of {P}ermanent {I}nfrastructures for {C}ontinuous {S}pace-based {M}onitoring of {N}atural {H}azards},
  urldate = {2022-01-09},
  publisher = {EARSeL},
  author = {Kakoullis, D. and Fotiou, K. and Melillos, G. and Danezis, C.},
  month = jun,
  year = {2021},
  booktitle = {40th EARSEL Symposium},
  file = {Snapshot:/Users/chrisdanezis/Zotero/storage/XNUA48MI/citations.html:text/html},
  }

• K. Fotiou, D. Kakoullis, M. Pekri, G. Melillos, R. Brcic, M. Eineder, D. G. Hadjimitsis, and C. Danezis. Space-based Deformation Monitoring of Coastal Urban Areas: The Case of Limassol’s Coastal Front. In 40th earsel symposium. Earsel, jun 2021.
  [BibTeX] [Abstract] [Download PDF]
  

  K Fotiou, D Kakoullis, M Pekri, G Melillos, R Brcic, M Eineder, D Hadjimitsis, C Danezis, 2021

  @inproceedings{fotiou2021earsel,
  title = {{Space}-based {Deformation} {Monitoring} of {Coastal} {Urban} {Areas}: {The} {Case} of {Limassol}’s {Coastal} {Front}},
  shorttitle = {{Space}-based {Deformation} {Monitoring} of {Coastal} {Urban} {Areas}},
  url = {https://scholar.google.com/citations?view_op=view_citation&hl=en&user=jnD3XAsAAAAJ&sortby=pubdate&alert_preview_top_rm=2&citation_for_view=jnD3XAsAAAAJ:hFOr9nPyWt4C},
  abstract = {K Fotiou, D Kakoullis, M Pekri, G Melillos, R Brcic, M Eineder, D Hadjimitsis, C Danezis, 2021},
  urldate = {2022-01-09},
  publisher = {EARSeL},
  author = {Fotiou, K. and Kakoullis, D. and Pekri, M. and Melillos, G. and Brcic, R. and Eineder, M. and Hadjimitsis, D. G. and Danezis, C.},
  month = jun,
  year = {2021},
  booktitle = {40th EARSEL Symposium},
  file = {Snapshot:/Users/chrisdanezis/Zotero/storage/XNUA48MI/citations.html:text/html},
  }

• M. Pekri, D. Kakoullis, M. Nikolaidis, E. Akylas, and C. Danezis. Estimation of Mean Sea Surface Height Variability in Cyprus using Tide Gauge and Sentinel-3 Satellite Altimetry Data. In 40th earsel symposium. Earsel, jun 2021.
  [BibTeX]

  @inproceedings{pekri2021earsel,
  title = {Estimation of {M}ean {S}ea {S}urface {H}eight {V}ariability in {C}yprus using {T}ide {G}auge and {S}entinel-3 {S}atellite {A}ltimetry {D}ata},
  urldate = {2022-01-09},
  publisher = {EARSeL},
  author = {Pekri, M. and Kakoullis, D. and Nikolaidis, M. and Akylas, E. and Danezis, C.},
  month = jun,
  year = {2021},
  booktitle = {40th EARSEL Symposium},
  file = {Snapshot:/Users/chrisdanezis/Zotero/storage/XNUA48MI/citations.html:text/html},
  }

• I. Kountouri, C. Danezis, A. Agapiou, N. Kyriakides, K. Themistocleous, P. Kyriakidis, H. Kontoes, E. Akylas, S. Michailides, and D. Hadjimitsis. A multi-disciplinary Integrated Approach using Earth Observation, GIS, Hydraulic Modelling for Flood Risk Assessment in Catchment Areas in Cyprus. In 40th earsel symposium. Earsel, jun 2021.
  [BibTeX] [Download PDF]

  @inproceedings{kountouri2021earsel,
  title = {A Multi-disciplinary {I}ntegrated {A}pproach using {E}arth {O}bservation, {GIS}, {H}ydraulic {M}odelling for {F}lood {R}isk {A}ssessment in {C}atchment {A}reas in {C}yprus},
  url = {https://scholar.google.com/citations?view_op=view_citation&hl=en&user=jnD3XAsAAAAJ&sortby=pubdate&alert_preview_top_rm=2&citation_for_view=jnD3XAsAAAAJ:hFOr9nPyWt4C},
  urldate = {2022-01-09},
  publisher = {EARSeL},
  author = {Kountouri, I. and Danezis, C. and Agapiou, A. and Kyriakides, N. and Themistocleous, K. and Kyriakidis, P. and Kontoes, H. and Akylas, E. and Michailides, S. and Hadjimitsis, D.},
  month = jun,
  year = {2021},
  booktitle = {40th EARSEL Symposium},
  file = {Snapshot:/Users/chrisdanezis/Zotero/storage/XNUA48MI/citations.html:text/html},
  }

• C. Danezis. The Role of Strategic Infrastructures for Space-based Earth Observation vis-a-vis Resilient Societies: The Example of CyCLOPS. In Third Phase of the Consultation Forum for Sustainable Energy in the Defence and Security Sector (CF SEDSS III), Online, November 2021. European defence agency.
  [BibTeX] [Download PDF]

  @inproceedings{danezis_eda_2021,
  type = {Invited {S}peaker},
  title = {The {R}ole of {S}trategic {I}nfrastructures for {S}pace-based {E}arth {O}bservation vis-a-vis {R}esilient {S}ocieties: {T}he {E}xample of {CyCLOPS}},
  author = {Danezis, C.},
  year = {2021},
  month = {November},
  address = {Online},
  booktitle = {{T}hird {P}hase of the {C}onsultation {F}orum for {S}ustainable {E}nergy in the {D}efence and {S}ecurity {S}ector {(CF SEDSS III)}},
  publisher = {European Defence Agency},
  url = {https://eden.eda.europa.eu/}
  }

• C. Danezis. Examples of MATLAB Integration in Civil Engineering & Geomatics Curricula. In Matlab & Simulink MENA Academic Forum, Online, March 2021. Mathworks.
  [BibTeX] [Download PDF]

  @inproceedings{danezis_mathworks_2021,
  type = {Invited {Speaker}},
  title = {Examples of {MATLAB} {Integration} in {Civil} {Engineering} \& {Geomatics} {Curricula}},
  author = {Danezis, C.},
  address = {Online},
  month = {March},
  year = {2021},
  booktitle = {MATLAB \& {Simulink} {MENA} {Academic} {Forum}},
  publisher = {MathWorks},
  url = {https://www.mathworks.com/company/events/webinars/upcoming/matlab-simulink-mena-academic-forum-3346788.html}
  }

2020

• C. Danezis, M. Nikolaidis, C. Mettas, D. G. Hadjimitsis, G. Kokosis, and C. Kleanthous. Establishing an Integrated Permanent Sea-Level Monitoring Infrastructure towards the Implementation of Maritime Spatial Planning in Cyprus. Journal of Marine Science and Engineering, 8(11):861, November 2020. doi:10.3390/jmse8110861
  [BibTeX] [Abstract] [Download PDF]
  

  The Maritime Spatial Planning is a piece of legislation (2014/89/EU) of the European Union that must be implemented by all member countries to enable management of their waters in a more coherent way to reduce conflicts, encourage investments, increase cross-border cooperation and protect the environment. Cyprus and Greece are working together in the frame of the THALCHOR2 project to implement this directive. From the Cyprus point of view, this directive has been a unique opportunity to modernize its Hydrographic and Geodetic Infrastructure to enable and facilitate the generation of reliable marine geospatial information. Concordantly, a network of integrated state-of-the-art multi-sensor stations has been established along the shoreline of the government-controlled territories to seamlessly monitor sea level, vertical crustal motion and meteorological parameters. This research provides insight into the implementation of this infrastructure and the data processing workflow to determine tidal levels. Furthermore, the first results acquired after exploiting two years of observations are presented along with initial aspects concerning mean sea-level variability in the Southeastern Mediterranean region.

  @article{danezis_establishing_2020,
  title = {Establishing an {Integrated} {Permanent} {Sea}-{Level} {Monitoring} {Infrastructure} towards the {Implementation} of {Maritime} {Spatial} {Planning} in {Cyprus}},
  volume = {8},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  url = {https://www.mdpi.com/2077-1312/8/11/861},
  doi = {10.3390/jmse8110861},
  abstract = {The Maritime Spatial Planning is a piece of legislation (2014/89/EU) of the European Union that must be implemented by all member countries to enable management of their waters in a more coherent way to reduce conflicts, encourage investments, increase cross-border cooperation and protect the environment. Cyprus and Greece are working together in the frame of the THALCHOR2 project to implement this directive. From the Cyprus point of view, this directive has been a unique opportunity to modernize its Hydrographic and Geodetic Infrastructure to enable and facilitate the generation of reliable marine geospatial information. Concordantly, a network of integrated state-of-the-art multi-sensor stations has been established along the shoreline of the government-controlled territories to seamlessly monitor sea level, vertical crustal motion and meteorological parameters. This research provides insight into the implementation of this infrastructure and the data processing workflow to determine tidal levels. Furthermore, the first results acquired after exploiting two years of observations are presented along with initial aspects concerning mean sea-level variability in the Southeastern Mediterranean region.},
  language = {en},
  number = {11},
  urldate = {2020-11-06},
  journal = {Journal of {Marine} {Science} and {Engineering}},
  author = {Danezis, C. and Nikolaidis, M. and Mettas, C. and Hadjimitsis, D. G. and Kokosis, G. and Kleanthous, C.},
  month = {November},
  year = {2020},
  keywords = {Cyprus, marine spatial planning, mean sea level, tidal data, tide gauge},
  pages = {861},
  verba = {2.2.13}
  }

• Y. Vacanas and C. Danezis. Determination of Effective Delay-Avoidance Practices in Construction Projects. Journal of Legal Affairs and Dispute Resolution in Engineering and Construction, 13(1):4520039, October 2020. doi:10.1061/(ASCE)LA.1943-4170.0000438
  [BibTeX] [Abstract] [Download PDF]
  

  Delay poses a significant issue for the worldwide construction industry and national economies. Numerous research endeavors have been carried out to shed light on the sources of delay, among which some employ statistical approaches to consider the perceptions of the industry’s main stakeholders. However, only a few suggest practices for delay mitigation but without considering their importance as perceived by the involved parties, which is crucial for appreciating their acceptance by the stakeholders and assess their immediate applicability. This research proposes an integrated statistical approach to determine the main delay sources, and identify the most effective, commonly accepted practices to promote delay mitigation. The perception of stakeholders was investigated via parametric and nonparametric methods. The results showed that, although there is an a priori disagreement in the perception of each party with respect to delay responsibility, commonly accepted delay mitigation practices can be successfully identified and thereby proposed.

  @article{vacanas_determination_2020,
  title = {Determination of {Effective} {Delay}-{Avoidance} {Practices} in {Construction} {Projects}},
  volume = {13},
  copyright = {© 2020 American Society of Civil Engineers},
  issn = {1943-4170},
  url = {https://ascelibrary.org/doi/abs/10.1061/%28ASCE%29LA.1943-4170.0000438},
  doi = {10.1061/(ASCE)LA.1943-4170.0000438},
  abstract = {Delay poses a significant issue for the worldwide construction industry and national economies. Numerous research endeavors have been carried out to shed light on the sources of delay, among which some employ statistical approaches to consider the perceptions of the industry’s main stakeholders. However, only a few suggest practices for delay mitigation but without considering their importance as perceived by the involved parties, which is crucial for appreciating their acceptance by the stakeholders and assess their immediate applicability. This research proposes an integrated statistical approach to determine the main delay sources, and identify the most effective, commonly accepted practices to promote delay mitigation. The perception of stakeholders was investigated via parametric and nonparametric methods. The results showed that, although there is an a priori disagreement in the perception of each party with respect to delay responsibility, commonly accepted delay mitigation practices can be successfully identified and thereby proposed.},
  language = {EN},
  number = {1},
  urldate = {2020-12-03},
  journal = {Journal of {Legal} {Affairs} and {Dispute} {Resolution} in {Engineering} and {Construction}},
  author = {Vacanas, Y. and Danezis, C.},
  month = {October},
  year = {2020},
  publisher = {American {Society} of {Civil} {Engineers}},
  keywords = {Construction, Cyprus, Delay, Delay avoidance, Delay mitigation, Measures, Project management},
  pages = {04520039},
  verba = {2.2.12}
  }

• M. Tzouvaras, C. Danezis, and D. G. Hadjimitsis. Small Scale Landslide Detection Using Sentinel-1 Interferometric SAR Coherence. Remote sensing, 12(10):1560, January 2020. doi:10.3390/rs12101560
  [BibTeX] [Abstract] [Download PDF]
  

  Infrastructure is operational under normal circumstances and is designed to cope with common natural disruptions such as rainfall and snow. Natural hazards can lead to severe problems at the areas where such phenomena occur, but also at neighboring regions as they can make parts of a road network virtually impassable. Landslides are one of the most devastating natural hazards worldwide, triggered by various factors that can be monitored via ground-based and/or satellite-based techniques. Cyprus is in an area of high susceptibility to such phenomena. Currently, extensive field campaigns including geotechnical drilling investigations and geophysical excavations are conducted to monitor land movements, and, at the same time, determine the geological suitability of areas. Active satellite remote sensors, namely Synthetic Aperture Radar (SAR), have been widely used for detecting and monitoring landslides and other ground deformation phenomena using Earth Observation based techniques. This paper aims to demonstrate how the use of Copernicus open-access and freely distributed datasets along with the exploitation of the open-source processing software SNAP (Sentinel’s Application Platform), provided by the European Space Agency, can be used for landslide detection, as in the case study near Pissouri, where a landslide was triggered by heavy rainfall on 15 February 2019, which caused a major disturbance to everyday commuters since the motorway connecting the cities of Limassol and Paphos remained closed for more than a month. The Coherent Change Detection (CCD) methodology was applied successfully by detecting the phenomenon under study accurately, using two indicators (the coherence difference and the normalized coherence difference). Receiver Operating Characteristic (ROC) analysis was carried out to measure their performance with the coherence difference having an overall accuracy of 93\% and the normalized coherence difference having an overall accuracy of 94.8\% for detecting the landslide and non-landslide areas. The probability of landslide detection was 63.2\% in the case of the coherence difference and increased to 73.7\% for the normalized coherence difference, whereas the probability of false alarm for both indicators was approximately 1\%.

  @article{tzouvaras_small_2020,
  title = {Small {Scale} {Landslide} {Detection} {Using} {Sentinel}-1 {Interferometric} {SAR} {Coherence}},
  volume = {12},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  url = {https://www.mdpi.com/2072-4292/12/10/1560},
  doi = {10.3390/rs12101560},
  abstract = {Infrastructure is operational under normal circumstances and is designed to cope with common natural disruptions such as rainfall and snow. Natural hazards can lead to severe problems at the areas where such phenomena occur, but also at neighboring regions as they can make parts of a road network virtually impassable. Landslides are one of the most devastating natural hazards worldwide, triggered by various factors that can be monitored via ground-based and/or satellite-based techniques. Cyprus is in an area of high susceptibility to such phenomena. Currently, extensive field campaigns including geotechnical drilling investigations and geophysical excavations are conducted to monitor land movements, and, at the same time, determine the geological suitability of areas. Active satellite remote sensors, namely Synthetic Aperture Radar (SAR), have been widely used for detecting and monitoring landslides and other ground deformation phenomena using Earth Observation based techniques. This paper aims to demonstrate how the use of Copernicus open-access and freely distributed datasets along with the exploitation of the open-source processing software SNAP (Sentinel\’s Application Platform), provided by the European Space Agency, can be used for landslide detection, as in the case study near Pissouri, where a landslide was triggered by heavy rainfall on 15 February 2019, which caused a major disturbance to everyday commuters since the motorway connecting the cities of Limassol and Paphos remained closed for more than a month. The Coherent Change Detection (CCD) methodology was applied successfully by detecting the phenomenon under study accurately, using two indicators (the coherence difference and the normalized coherence difference). Receiver Operating Characteristic (ROC) analysis was carried out to measure their performance with the coherence difference having an overall accuracy of 93\% and the normalized coherence difference having an overall accuracy of 94.8\% for detecting the landslide and non-landslide areas. The probability of landslide detection was 63.2\% in the case of the coherence difference and increased to 73.7\% for the normalized coherence difference, whereas the probability of false alarm for both indicators was approximately 1\%.},
  language = {en},
  number = {10},
  urldate = {2020-12-03},
  journal = {Remote Sensing},
  author = {Tzouvaras, M. and Danezis, C. and Hadjimitsis, D. G.},
  month = {January},
  year = {2020},
  keywords = {CCD, change detection, coherence, Copernicus, early warning systems, landslides, rainfall, SAR, Sentinel-1},
  pages = {1560},
  verba = {2.2.11}
  }

• M. Tzouvaras, C. Danezis, and D. G. Hadjimitsis. Differential SAR Interferometry Using Sentinel-1 Imagery-Limitations in Monitoring Fast Moving Landslides: The Case Study of Cyprus. Geosciences, 10(6):236, June 2020. doi:10.3390/geosciences10060236
  [BibTeX] [Abstract] [Download PDF]
  

  Cyprus, being located on the Mediterranean fault zone, exhibits a unique geodynamic regime since its tectonic evolution is driven by the interaction of the Eurasian and African plate. Besides its seismological interest, many active landslides and slope instabilities in areas of steep topography occur in Cyprus, having substantial impact on the built environment, by posing an imminent threat for entire settlements and critical infrastructure. Moreover, extreme meteorological events occur rarely, like severe rainfall and thunderstorms, that combined with the geological properties in some areas and the seismically stressed ground, can lead to landslides, causing severe damages to critical infrastructure. In the present study, the DInSAR methodology is applied for the detection of two individual landslide events that were triggered by heavy rainfall in Limassol and Paphos Districts in February 2019. Six co-event interferometric Synthetic Aperture Radar (SAR) pairs were used to produce displacement maps in vertical and east-west directions to study the resulting slope deformations. The above are carried out using Sentinel-1 imagery that are freely provided under the Copernicus umbrella. The limitations that arise from the speed and complexity of the deformations under study and the adverse residing meteorological conditions that caused these phenomena are investigated, as found in literature. Indeed, the sparse vegetation at the slopes affected by the landslides, the residing meteorological conditions, the heavy rainfall that triggered the two landslides, and the temporal phase aliasing effect due to the speed of the ground deformation were found to be the main limitations for the application of DInSAR methodology, resulting in the underestimation of the ground deformation that occurred.

  @article{tzouvaras_differential_2020,
  title = {Differential {SAR} {Interferometry} {Using} {Sentinel}-1 {Imagery}-{Limitations} in {Monitoring} {Fast} {Moving} {Landslides}: {The} {Case} {Study} of {Cyprus}},
  volume = {10},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  shorttitle = {Differential {SAR} {Interferometry} {Using} {Sentinel}-1 {Imagery}-{Limitations} in {Monitoring} {Fast} {Moving} {Landslides}},
  url = {https://www.mdpi.com/2076-3263/10/6/236},
  doi = {10.3390/geosciences10060236},
  abstract = {Cyprus, being located on the Mediterranean fault zone, exhibits a unique geodynamic regime since its tectonic evolution is driven by the interaction of the Eurasian and African plate. Besides its seismological interest, many active landslides and slope instabilities in areas of steep topography occur in Cyprus, having substantial impact on the built environment, by posing an imminent threat for entire settlements and critical infrastructure. Moreover, extreme meteorological events occur rarely, like severe rainfall and thunderstorms, that combined with the geological properties in some areas and the seismically stressed ground, can lead to landslides, causing severe damages to critical infrastructure. In the present study, the DInSAR methodology is applied for the detection of two individual landslide events that were triggered by heavy rainfall in Limassol and Paphos Districts in February 2019. Six co-event interferometric Synthetic Aperture Radar (SAR) pairs were used to produce displacement maps in vertical and east-west directions to study the resulting slope deformations. The above are carried out using Sentinel-1 imagery that are freely provided under the Copernicus umbrella. The limitations that arise from the speed and complexity of the deformations under study and the adverse residing meteorological conditions that caused these phenomena are investigated, as found in literature. Indeed, the sparse vegetation at the slopes affected by the landslides, the residing meteorological conditions, the heavy rainfall that triggered the two landslides, and the temporal phase aliasing effect due to the speed of the ground deformation were found to be the main limitations for the application of DInSAR methodology, resulting in the underestimation of the ground deformation that occurred.},
  language = {en},
  number = {6},
  urldate = {2020-12-03},
  journal = {Geosciences},
  author = {Tzouvaras, M. and Danezis, C. and Hadjimitsis, D. G.},
  month = {June},
  year = {2020},
  publisher = {Multidisciplinary Digital Publishing Institute},
  keywords = {Copernicus, DInSAR, interferometry, landslides, limitations, SAR, slope deformation},
  pages = {236},
  verba = {2.2.10}
  }

• C. Danezis, M. Chatzinikos, and C. Kotsakis. Linear and Nonlinear Deformation Effects in the Permanent GNSS Network of Cyprus. Sensors, 20(6):1768, January 2020. doi:10.3390/s20061768
  [BibTeX] [Abstract] [Download PDF]
  

  Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.

  @article{danezis_linear_2020,
  title = {Linear and {Nonlinear} {Deformation} {Effects} in the {Permanent} {GNSS} {Network} of {Cyprus}},
  volume = {20},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  url = {https://www.mdpi.com/1424-8220/20/6/1768},
  doi = {10.3390/s20061768},
  abstract = {Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011\–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.},
  language = {en},
  number = {6},
  urldate = {2020-12-03},
  journal = {Sensors},
  author = {Danezis, C. and Chatzinikos, M. and Kotsakis, C.},
  month = {January},
  year = {2020},
  publisher = {Multidisciplinary Digital Publishing Institute},
  keywords = {CORS, crustal deformation, Cyprus, GNSS, position timeseries, seasonal variations, station velocities},
  pages = {1768},
  verba = {2.2.8}
  }

• D. Hadjimitsis, G. Leventis, D. Cerra, K. Themistocleous, P. Kyriakidis, A. Agapiou, D. Makri, N. Papageorgiou, C. Danezis, V. Lysandrou, and others. ‘EXCELSIOR’ H2020 Widespread Teaming Phase 2 Project: Earth Observation and Geoinformatics Research and Innovation Agenda for Cultural Heritage. In Proceedings of euromed 2020: digital heritage. progress in cultural heritage: documentation, preservation, and protection, page 150–161. Springer,, 2020.
  [BibTeX]

  @inproceedings{hadjimitsis2020excelsior,
  title={{‘EXCELSIOR’ H2020} {W}idespread {T}eaming {P}hase 2 {P}roject: {E}arth {O}bservation and {G}eoinformatics {R}esearch and {I}nnovation {A}genda for {C}ultural {H}eritage},
  author={Hadjimitsis, D. and Leventis, G. and Cerra, D. and Themistocleous, K. and Kyriakidis, P. and Agapiou, A. and Makri, D. and Papageorgiou, N. and Danezis, C. and Lysandrou, V. and others},
  booktitle={Proceedings of EuroMed 2020: Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and Protection},
  pages={150--161},
  year={2020},
  organization={Springer}
  }

• G. Melillos, K. Themistocleous, C. Danezis, S. Michaelides, D. G. Hadjimitsis, S. Jacobsen, and B. Tings. The Use of Remote Sensing for Maritime Surveillance for Security and Safety in Cyprus. In Detection and Sensing of Mines, Explosive Objects, and Obscured Targets XXV, volume 11418, page 114180J. International society for optics and photonics, April 2020. doi:10.1117/12.2567102
  [BibTeX] [Abstract] [Download PDF]
  

  Maritime surveillance is of critical importance for threat prevention and maintenance of national security and safety. Maritime traffic comprises worldwide navigation of millions of vessels. In this sense, the geostrategic position of Cyprus entails the need for effective monitoring of marine traffic. Remote Sensing is a technique, which enables maritime surveillance by means of space-based detection and identification of marine traffic. The advent of new satellite missions, such as Sentinel-1, enabled the acquisition of systematic datasets for monitoring vessels. Using the Copernicus Open Access Hub service, it is now feasible to access satellite data in a fully automated and near real-time mode and deliver vessel information through a web portal interface. Nevertheless, there is still a great need to understand the full potential of the information acquired from such sensors. In this paper, an overview of vessel tracking techniques using Sentinel acquisitions is carried out. Consequently, vessel detections via space imagery could be authenticated against Automatic Identification System (AIS) data, which provide the location and dimensions of ships that are legally operating in the Cyprus region.

  @inproceedings{melillos_use_2020,
  title = {The {U}se of {R}emote {S}ensing for {M}aritime {S}urveillance for {S}ecurity and {S}afety in {Cyprus}},
  volume = {11418},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11418/114180J/The-use-of-remote-sensing-for-maritime-surveillance-for-security/10.1117/12.2567102.short},
  doi = {10.1117/12.2567102},
  abstract = {Maritime surveillance is of critical importance for threat prevention and maintenance of national security and safety. Maritime traffic comprises worldwide navigation of millions of vessels. In this sense, the geostrategic position of Cyprus entails the need for effective monitoring of marine traffic. Remote Sensing is a technique, which enables maritime surveillance by means of space-based detection and identification of marine traffic. The advent of new satellite missions, such as Sentinel-1, enabled the acquisition of systematic datasets for monitoring vessels. Using the Copernicus Open Access Hub service, it is now feasible to access satellite data in a fully automated and near real-time mode and deliver vessel information through a web portal interface. Nevertheless, there is still a great need to understand the full potential of the information acquired from such sensors. In this paper, an overview of vessel tracking techniques using Sentinel acquisitions is carried out. Consequently, vessel detections via space imagery could be authenticated against Automatic Identification System (AIS) data, which provide the location and dimensions of ships that are legally operating in the Cyprus region.},
  urldate = {2020-12-03},
  booktitle = {Detection and {Sensing} of {Mines}, {Explosive} {Objects}, and {Obscured} {Targets} {XXV}},
  publisher = {International Society for Optics and Photonics},
  author = {Melillos, G. and Themistocleous, K. and Danezis, C. and Michaelides, S. and Hadjimitsis, D. G. and Jacobsen, S. and Tings, B.},
  month = {April},
  year = {2020},
  pages = {114180J}
  }

• D. G. Hadjimitsis, P. Kyriakides, C. Danezis, E. Akylas, N. Kyriakides, C. Papoutsa, K. Themistocleous, R. Mammouri, A. Nisantzi, A. Agapiou, C. Mettas, M. Tzouvaras, M. Prodromou, E. Loulli, G. Melillos, V. Lysandrou, D. Antoniades, A. Christofe, H. Kontoes, G. Schreier, A. Ansmann, S. Michaelides, A. Evagorou, E. Anastasiou, T. Polydorou, K. Neocleous, M. Miltiadou, E. Evagorou, C. Theocharides, G. Leventis, A. Anayiotos, S. Tziortzis, and G. Komodromos. Exploring the Importance for Promoting Earth Observation in Education. In Earth Resources and Environmental Remote Sensing/GIS Applications XI, volume 11534, page 1153416. International society for optics and photonics, September 2020. doi:10.1117/12.2574134
  [BibTeX] [Abstract] [Download PDF]
  

  This paper presents the significance and importance of promoting the benefits of Earth Observation when implemented in ‘secondary’ and ‘higher education’ in Cyprus schools. Firstly, examples of how Earth observation is used in other countries for the secondary education such as Germany and China and how ESA through Earth Observation education materials are used to promote STEM education are presented. Secondly, ‘EXCELSIOR for Schools’ & ‘SOFIA ESA’ initiatives for promoting earth observation education in Cyprus are also presented. Indeed. examples of how earth observation is presented through seminars, workshops, science cafes, researcher’s night, from earth observation experts into schools in Cyprus is also described and analysed. Examples of how earth observation is used in the existing curriculum for undergraduate, postgraduate courses for surveying and civil engineers is demonstrated for monitoring and providing solutions for civil and geomatics engineering aspects at the Cyprus University of Technology through the EXCELSIOR H2020 Teaming project.

  @inproceedings{hadjimitsis_exploring_2020,
  title = {Exploring the {I}mportance for {P}romoting {E}arth {O}bservation in {E}ducation},
  volume = {11534},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11534/1153416/Exploring-the-importance-for-promoting-Earth-observation-in-education/10.1117/12.2574134.short},
  doi = {10.1117/12.2574134},
  abstract = {This paper presents the significance and importance of promoting the benefits of Earth Observation when implemented in ‘secondary’ and ‘higher education’ in Cyprus schools. Firstly, examples of how Earth observation is used in other countries for the secondary education such as Germany and China and how ESA through Earth Observation education materials are used to promote STEM education are presented. Secondly, ‘EXCELSIOR for Schools’ \& ‘SOFIA ESA’ initiatives for promoting earth observation education in Cyprus are also presented. Indeed. examples of how earth observation is presented through seminars, workshops, science cafes, researcher's night, from earth observation experts into schools in Cyprus is also described and analysed. Examples of how earth observation is used in the existing curriculum for undergraduate, postgraduate courses for surveying and civil engineers is demonstrated for monitoring and providing solutions for civil and geomatics engineering aspects at the Cyprus University of Technology through the EXCELSIOR H2020 Teaming project.},
  urldate = {2020-12-03},
  booktitle = {Earth {Resources} and {Environmental} {Remote} {Sensing}/{GIS} {Applications} {XI}},
  publisher = {International Society for Optics and Photonics},
  author = {Hadjimitsis, D. G. and Kyriakides, P. and Danezis, C. and Akylas, E. and Kyriakides, N. and Papoutsa, C. and Themistocleous, K. and Mammouri, R. and Nisantzi, A. and Agapiou, A. and Mettas, C. and Tzouvaras, M. and Prodromou, M. and Loulli, E. and Melillos, G. and Lysandrou, V. and Antoniades, D. and Christofe, A. and Kontoes, H. and Schreier, G. and Ansmann, A. and Michaelides, S. and Evagorou, A. and Anastasiou, E. and Polydorou, T. and Neocleous, K. and Miltiadou, M. and Evagorou, E. and Theocharides, C. and Leventis, G. and Anayiotos, A. and Tziortzis, S. and Komodromos, G.},
  month = {September},
  year = {2020},
  pages = {1153416}
  }

• D. Kakoullis and C. Danezis. Permanent Infrastructures for Continuous Space-based Monitoring of Natural Hazards. In Eighth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2020), volume 11524, page 115241F. International society for optics and photonics (spie), August 2020. doi:10.1117/12.2571201
  [BibTeX] [Abstract] [Download PDF]
  

  The global exposure of population and the built environment to natural hazards has significantly increased over the last decades. Consequently, important initiatives, such as the SENDAI framework for disaster risk reduction have risen to promote a global culture of effective disaster reduction policies, including mitigation actions on the social and economic impact of geohazards. Efficient prevention and mitigation rely on meticulous observation and monitoring of geohazards triggering factors using space- and ground-based techniques. The most prominent space techniques are Global Navigation Satellite Systems (GNSS) and Synthetic Aperture Radar (SAR) satellite missions. The combination of GNSS and SAR observables through the integration of CORS networks and Corner Reflector arrays forms a seamless and continuous ground displacement monitoring system. The purpose of this paper is to present current permanent infrastructures dedicated in space-based deformation monitoring, perform analysis of their instrumentation, review their monumentation types and procedures, and examine the required spatial distribution of network multi-sensor stations. Finally, CyCLOPS, a new regional integrated monitoring system, which enables robust and seamless monitoring of earthquake and landslide activity in Cyprus and the Southeastern Mediterranean Region is presented in this paper.

  @inproceedings{kakoullis_permanent_2020,
  title = {Permanent {I}nfrastructures for {C}ontinuous {S}pace-based {M}onitoring of {N}atural {H}azards},
  volume = {11524},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11524/115241F/Permanent-infrastructures-for-continuous-space-based-monitoring-of-natural-hazards/10.1117/12.2571201.short},
  doi = {10.1117/12.2571201},
  abstract = {The global exposure of population and the built environment to natural hazards has significantly increased over the last decades. Consequently, important initiatives, such as the SENDAI framework for disaster risk reduction have risen to promote a global culture of effective disaster reduction policies, including mitigation actions on the social and economic impact of geohazards. Efficient prevention and mitigation rely on meticulous observation and monitoring of geohazards triggering factors using space- and ground-based techniques. The most prominent space techniques are Global Navigation Satellite Systems (GNSS) and Synthetic Aperture Radar (SAR) satellite missions. The combination of GNSS and SAR observables through the integration of CORS networks and Corner Reflector arrays forms a seamless and continuous ground displacement monitoring system. The purpose of this paper is to present current permanent infrastructures dedicated in space-based deformation monitoring, perform analysis of their instrumentation, review their monumentation types and procedures, and examine the required spatial distribution of network multi-sensor stations. Finally, CyCLOPS, a new regional integrated monitoring system, which enables robust and seamless monitoring of earthquake and landslide activity in Cyprus and the Southeastern Mediterranean Region is presented in this paper.},
  urldate = {2020-12-03},
  booktitle = {Eighth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2020})},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Kakoullis, D. and Danezis, C.},
  month = {August},
  year = {2020},
  pages = {115241F}
  }

• M. Nikolaidis and C. Danezis. An Initial Overview of Tidal and Sea Level Variability in Cyprus. In Eighth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2020), volume 11524, page 1152423. International society for optics and photonics (spie), August 2020. doi:10.1117/12.2571166
  [BibTeX] [Abstract] [Download PDF]
  

  Tide gauges remain the fundamental instrument used to measure water level in the coastal environment. Issues surrounding the calibration and vertical datum control of tide gauges are therefore fundamental in studies involving the determination of absolute sea level and its variation over time. In this article, we collected and analyzed data from five tide gauge stations, located in strategic positions around the Cyprus island. During the analysis the following tidal datums were determined: Mean Sea Level (MSL), Mean Tide Level (MTL), Mean High Water (MHW), Mean Higher High Water (MHHW), Mean Low Water (MLW) and Mean Lower Low Water (MLLW). These were calculated temporarily using the available data observed since December 2019. Using the Doodson X0 filter for suppressing the effect of the astronomical tide on the MSL, this preliminary methodology provides some insight regarding the Absolute Mean Sea Level and Mean Tide Level of Cyprus.

  @inproceedings{nikolaidis_initial_2020,
  title = {An {I}nitial {O}verview of {T}idal and {S}ea {L}evel {V}ariability in {C}yprus},
  volume = {11524},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11524/1152423/An-initial-overview-of-tidal-and-sea-level-variability-in/10.1117/12.2571166.short},
  doi = {10.1117/12.2571166},
  abstract = {Tide gauges remain the fundamental instrument used to measure water level in the coastal environment. Issues surrounding the calibration and vertical datum control of tide gauges are therefore fundamental in studies involving the determination of absolute sea level and its variation over time. In this article, we collected and analyzed data from five tide gauge stations, located in strategic positions around the Cyprus island. During the analysis the following tidal datums were determined: Mean Sea Level (MSL), Mean Tide Level (MTL), Mean High Water (MHW), Mean Higher High Water (MHHW), Mean Low Water (MLW) and Mean Lower Low Water (MLLW). These were calculated temporarily using the available data observed since December 2019. Using the Doodson X0 filter for suppressing the effect of the astronomical tide on the MSL, this preliminary methodology provides some insight regarding the Absolute Mean Sea Level and Mean Tide Level of Cyprus.},
  urldate = {2020-12-03},
  booktitle = {Eighth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2020})},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Nikolaidis, M. and Danezis, C.},
  month = {August},
  year = {2020},
  pages = {1152423}
  }

• K. Fotiou and C. Danezis. An Overview of Electronic Corner Reflectors and their Use in Ground Deformation Monitoring Applications. In Eighth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2020), volume 11524, page 115240N. International society for optics and photonics (spie), August 2020. doi:10.1117/12.2571886
  [BibTeX] [Abstract] [Download PDF]
  

  Over the years, passive and active reflectors are becoming indispensable parts in ground deformation monitoring using Interferometric SAR geodetic techniques. The evolution and the need for more practical and compact in size reflectors motivated the implementation of Electronic Corner Reflectors, namely ECR Transponders. ECR Transponders are compact active permanent scatterers, which are used in the estimation of physical or man-induced deformation processes. Their main advantage lies their compact size and the fact that a sole unit accounts for both ascending and descending tracks, instead of having two opposite-facing ordinary Corner Reflectors configuration. To date, ECR transponders mainly operate in C-band and, thus, are compatible with Sentinel-1 and Radarsat. Although experiments are in initial stage, the results seem quite promising with respect to the classic passive corner reflectors in many sectors. In this paper, an analysis of the ECR-C band transponders is carried out, along with a worldwide overview and a comparison of their results in various application sectors using different satellite radar missions and techniques.

  @inproceedings{fotiou_overview_2020,
  title = {An {O}verview of {E}lectronic {C}orner {R}eflectors and their {U}se in {G}round {D}eformation {M}onitoring {A}pplications},
  volume = {11524},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11524/115240N/An-overview-of-electronic-corner-reflectors-and-their-use-in/10.1117/12.2571886.short},
  doi = {10.1117/12.2571886},
  abstract = {Over the years, passive and active reflectors are becoming indispensable parts in ground deformation monitoring using Interferometric SAR geodetic techniques. The evolution and the need for more practical and compact in size reflectors motivated the implementation of Electronic Corner Reflectors, namely ECR Transponders. ECR Transponders are compact active permanent scatterers, which are used in the estimation of physical or man-induced deformation processes. Their main advantage lies their compact size and the fact that a sole unit accounts for both ascending and descending tracks, instead of having two opposite-facing ordinary Corner Reflectors configuration. To date, ECR transponders mainly operate in C-band and, thus, are compatible with Sentinel-1 and Radarsat. Although experiments are in initial stage, the results seem quite promising with respect to the classic passive corner reflectors in many sectors. In this paper, an analysis of the ECR-C band transponders is carried out, along with a worldwide overview and a comparison of their results in various application sectors using different satellite radar missions and techniques.},
  urldate = {2020-12-03},
  booktitle = {Eighth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2020})},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Fotiou, K. and Danezis, C.},
  month = {August},
  year = {2020},
  pages = {115240N}
  }

• M. Pekri and C. Danezis. Estimation of Sea Level Height Variability in Cyprus using Sentinel-3 Satellite Altimetry Data. In Eighth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2020), volume 11524, page 1152427. International society for optics and photonics (spie), August 2020. doi:10.1117/12.2571949
  [BibTeX] [Abstract] [Download PDF]
  

  The advent of satellite altimetry brought a revolution in monitoring sea level height in ocean and offshore areas. Satellite altimetry missions are constantly evolving over time and provide valuable products that assist, among others, in the precise estimation of Mean Sea Level (MSL) and its periodic update. Over the recent years, MSL has seen a rapid rise, mainly due to climate change and the increase of global temperature, which accelerates the melting of onshore snow and ice reserves, along with the thermal expansion of the oceans. Concordantly, several islands and coastal regions face the danger of ‘drowning’ or flooding. Therefore, Cyprus, being an island in the Southeastern region of the Mediterranean Sea mandates the continuous monitoring of sea level to determine the risk of flooding, especially in coastal zones. This paper presents a first endeavor to estimate MSL in Cyprus using Copernicus Sentinel-3 altimetric data from 2016 to date. The results were validated against MSL observations from the Cyprus national tide gauge network and a discussion on the use of Sentinel- 3 data as an indispensable monitoring tool is carried out.

  @inproceedings{pekri_estimation_2020,
  title = {Estimation of {S}ea {L}evel {H}eight {V}ariability in {Cyprus} using {Sentinel}-3 {S}atellite {A}ltimetry {D}ata},
  volume = {11524},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11524/1152427/Estimation-of-sea-level-height-variability-in-Cyprus-using-Sentinel/10.1117/12.2571949.short},
  doi = {10.1117/12.2571949},
  abstract = {The advent of satellite altimetry brought a revolution in monitoring sea level height in ocean and offshore areas. Satellite altimetry missions are constantly evolving over time and provide valuable products that assist, among others, in the precise estimation of Mean Sea Level (MSL) and its periodic update. Over the recent years, MSL has seen a rapid rise, mainly due to climate change and the increase of global temperature, which accelerates the melting of onshore snow and ice reserves, along with the thermal expansion of the oceans. Concordantly, several islands and coastal regions face the danger of 'drowning' or flooding. Therefore, Cyprus, being an island in the Southeastern region of the Mediterranean Sea mandates the continuous monitoring of sea level to determine the risk of flooding, especially in coastal zones. This paper presents a first endeavor to estimate MSL in Cyprus using Copernicus Sentinel-3 altimetric data from 2016 to date. The results were validated against MSL observations from the Cyprus national tide gauge network and a discussion on the use of Sentinel- 3 data as an indispensable monitoring tool is carried out.},
  urldate = {2020-12-03},
  booktitle = {Eighth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2020})},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Pekri, M. and Danezis, C.},
  month = {August},
  year = {2020},
  pages = {1152427}
  }

• M. Prodromou, A. Yfantidou, C. Theocharidis, M. Miltiadou, and C. Danezis. Analysis of Radar and Thermal Satellite Data Time-series for Understanding the Long-term Impact of Land Surface Temperature Changes on Forests. In Egu general assembly 2020, volume 22, page 10582, May 2020.
  [BibTeX] [Abstract] [Download PDF]
  

  Forests are globally an important environmental and ecological resource since they retrain water through their routes and therefore limit flooding events and soil erosion from moderate rainfall. They also act as carbon sinks, provide food, clean water and natural habitat for humans and other species, including threatened ones. Recent reports stressed the vulnerability of EU forest ecosystem to climate change impacts (EEA, 2012) (IPPC, et al., 2014). Climate change is a significant factor in the increasing forest fires and tree species being unable to adapt to the severity and frequency of drought during the summer period. Consequently, the possibility of increased insect pests and tree diseases is high as trees have been weakened by the extreme weather conditions. In Cyprus, there are two types of pine trees that exists on Troodos mountains, Pinus Nigra and Pinus Brutia, that may have been influenced by the reduced snowfall and extended summer droughts during the last decades. The overarching aim of this project is to research the impact of Land Surface Temperature on Cypriot forests on Troodos mountains by analysing time-series of radar and thermal satellite data. Impacts may include forest decline that does not relate to fire events, decreased forest density and alternations to timing of forest blooming initiation, duration and termination. Radar systems emitted pulses that can penetrate forest canopy due to the size of its wavelength and, therefore, collect information between tree branches without being affected by clouds. This presentation will focus on radar analysis conducted; testing of various methods, and how the processing pipeline has been automated. The project ‘ASTARTE’ (EXCELLENCE/0918/0341) is co-financed by the European Regional Development Fund and the Republic of Cyprus through the Research Innovation Foundation.

  @inproceedings{prodromou_analysis_2020,
  title = {Analysis of {R}adar and {T}hermal {S}atellite {D}ata {T}ime-series for {U}nderstanding the {L}ong-term {I}mpact of {L}and {S}urface {T}emperature {C}hanges on {F}orests},
  volume = {22},
  url = {http://adsabs.harvard.edu/abs/2020EGUGA..2210582P},
  abstract = {Forests are globally an important environmental and ecological resource since they retrain water through their routes and therefore limit flooding events and soil erosion from moderate rainfall. They also act as carbon sinks, provide food, clean water and natural habitat for humans and other species, including threatened ones. Recent reports stressed the vulnerability of EU forest ecosystem to climate change impacts (EEA, 2012) (IPPC, et al., 2014). Climate change is a significant factor in the increasing forest fires and tree species being unable to adapt to the severity and frequency of drought during the summer period. Consequently, the possibility of increased insect pests and tree diseases is high as trees have been weakened by the extreme weather conditions. In Cyprus, there are two types of pine trees that exists on Troodos mountains, Pinus Nigra and Pinus Brutia, that may have been influenced by the reduced snowfall and extended summer droughts during the last decades. The overarching aim of this project is to research the impact of Land Surface Temperature on Cypriot forests on Troodos mountains by analysing time-series of radar and thermal satellite data. Impacts may include forest decline that does not relate to fire events, decreased forest density and alternations to timing of forest blooming initiation, duration and termination. Radar systems emitted pulses that can penetrate forest canopy due to the size of its wavelength and, therefore, collect information between tree branches without being affected by clouds. This presentation will focus on radar analysis conducted; testing of various methods, and how the processing pipeline has been automated. The project 'ASTARTE' (EXCELLENCE/0918/0341) is co-financed by the European Regional Development Fund and the Republic of Cyprus through the Research Innovation Foundation.},
  urldate = {2020-12-03},
  author = {Prodromou, M. and Yfantidou, A. and Theocharidis, C. and Miltiadou, M. and Danezis, C.},
  month = {May},
  year = {2020},
  booktitle = {EGU General Assembly 2020},
  pages = {10582}
  }

• Kyriacos Themistocleous and Chris Danezis. Monitoring Cultural Heritage Sites Affected by Geo-Hazards Using In Situ and SAR Data: The Choirokoitia Case Study. In D. G. Hadjimitsis, K. Themistocleous, B. Cuca, A. Agapiou, V. Lysandrou, R. Lasaponara, N. Masini, and G. Schreier, editors, Remote Sensing for Archaeology and Cultural Landscapes: Best Practices and Perspectives Across Europe and the Middle East, Springer Remote Sensing/Photogrammetry, page 285–308. Springer international publishing, 2020. doi:10.1007/978-3-030-10979-0_16
  [BibTeX] [Abstract] [Download PDF]
  

  This chapter focuses on the different methods for monitoring cultural heritage and archaeological sites affected by geo-hazards through the integrated method of using satellite imagery and field measurements. The Choirokoitia case study, which was one of the four UNESCO World Heritage list sites under the auspices of the PROTHEGO project, will be examined. PROTHEGO provides a new, low-cost methodological approach for the safe management of cultural heritage monuments and sites located in Europe, by integrating novel space technology based on interferometric synthetic aperture radar (InSAR), long-term low-impact monitoring systems and indirect analysis of environmental contexts to retrieve information on ground stability and motion in the 400+ UNESCO’s World Heritage List monuments and sites of Europe.

  @incollection{themistocleous_monitoring_2020-1,
  series = {Springer Remote Sensing/Photogrammetry},
  title = {Monitoring {Cultural} {Heritage} {Sites} {Affected} by {Geo}-{Hazards} {Using} {In} {Situ} and {SAR} {Data}: {The} {Choirokoitia} {Case} {Study}},
  isbn = {978-3-030-10979-0},
  shorttitle = {Monitoring {Cultural} {Heritage} {Sites} {Affected} by {Geo}-{Hazards} {Using} {In} {Situ} and {SAR} {Data}},
  url = {https://doi.org/10.1007/978-3-030-10979-0_16},
  abstract = {This chapter focuses on the different methods for monitoring cultural heritage and archaeological sites affected by geo-hazards through the integrated method of using satellite imagery and field measurements. The Choirokoitia case study, which was one of the four UNESCO World Heritage list sites under the auspices of the PROTHEGO project, will be examined. PROTHEGO provides a new, low-cost methodological approach for the safe management of cultural heritage monuments and sites located in Europe, by integrating novel space technology based on interferometric synthetic aperture radar (InSAR), long-term low-impact monitoring systems and indirect analysis of environmental contexts to retrieve information on ground stability and motion in the 400+ UNESCO’s World Heritage List monuments and sites of Europe.},
  language = {en},
  urldate = {2020-12-03},
  booktitle = {Remote {Sensing} for {Archaeology} and {Cultural} {Landscapes}: {Best} {Practices} and {Perspectives} {Across} {Europe} and the {Middle} {East}},
  publisher = {Springer International Publishing},
  author = {Themistocleous, Kyriacos and Danezis, Chris},
  editor = {Hadjimitsis, D. G. and Themistocleous, K. and Cuca, B. and Agapiou, A. and Lysandrou, V. and Lasaponara, R. and Masini, N. and Schreier, G.},
  year = {2020},
  doi = {10.1007/978-3-030-10979-0_16},
  keywords = {Archaeology, Cultural heritage, Geodetic techniques, Natural hazards, Photogrammetry, Remote sensing, UAV},
  pages = {285--308}
  }

• C. Danezis. CyCLOPS: A Strategic Research Infrastructure Unit for Geohazards Monitoring in Cyprus and the Southeastern Mediterranean Region. In 1st virtual excelsior international technical workshop, July 2020.
  [BibTeX] [Download PDF]

  @inproceedings{danezis_cyclops_2020,
  title = {{CyCLOPS}: {A} {Strategic} {Research} {Infrastructure} {Unit} for {Geohazards} {Monitoring} in {Cyprus} and the {Southeastern} {Mediterranean} {Region}},
  copyright = {Attribution-NonCommercial-NoDerivatives 4.0 International},
  shorttitle = {{CyCLOPS}},
  url = {https://ktisis.cut.ac.cy/handle/10488/19020},
  language = {en},
  urldate = {2020-12-03},
  booktitle = {1st Virtual EXCELSIOR International Technical Workshop},
  author = {Danezis, C.},
  month = {July},
  year = {2020}
  }

2019

• M. Tzouvaras, D. Kouhartsiouk, A. Agapiou, C. Danezis, and D. G. Hadjimitsis. The Use of Sentinel-1 Synthetic Aperture Radar (SAR) Images and Open-Source Software for Cultural Heritage: An Example from Paphos Area in Cyprus for Mapping Landscape Changes after a 5.6 Magnitude Earthquake. Remote sensing, 11(15):1766, January 2019. doi:10.3390/rs11151766
  [BibTeX] [Abstract] [Download PDF]
  

  Active satellite remote sensors have emerged in the last years in the field of archaeology, providing new tools for monitoring extensive cultural heritage landscapes and areas. These active sensors, namely synthetic aperture radar (SAR) satellites, provide systematic datasets for mapping land movements triggered from earthquakes, landslides, and so on. Copernicus, the European program for monitoring the environment, provides continuous radar datasets through the Sentinel-1 mission with an almost worldwide coverage. This paper aims to demonstrate how the use of open-access and freely distributed datasets such as those under the Copernicus umbrella, along with the exploitation of open-source radar processing software, namely the sentinel applications platform (SNAP) and SNAPHU tools, provided respectively by the European Space Agency (ESA) and the University of Stanford, can be used to extract an SAR interferogram in the wider area of Paphos, located in the western part of Cyprus. The city includes various heritage sites and monuments, some of them already included in the UNESCO World Heritage list. The interferogram was prepared to study the effects of an earthquake to the buildings and sites of the area. The earthquake of a 5.6 magnitude on the Richter scale was triggered on 15 April 2015 and was strongly felt throughout the whole island. The interferogram results were based on Differential Synthetic Aperture Radar Interferometry (D-InSAR) methodology, finding a maximum uplift of 74 mm and a maximum subsidence of 31 mm. The overall process and methodology are presented in this paper.

  @article{tzouvaras_use_2019,
  title = {The {Use} of {Sentinel}-1 {Synthetic} {Aperture} {Radar} ({SAR}) {Images} and {Open}-{Source} {Software} for {Cultural} {Heritage}: {An} {Example} from {Paphos} {Area} in {Cyprus} for {Mapping} {Landscape} {Changes} after a 5.6 {Magnitude} {Earthquake}},
  volume = {11},
  copyright = {http://creativecommons.org/licenses/by/3.0/},
  shorttitle = {The {Use} of {Sentinel}-1 {Synthetic} {Aperture} {Radar} ({SAR}) {Images} and {Open}-{Source} {Software} for {Cultural} {Heritage}},
  url = {https://www.mdpi.com/2072-4292/11/15/1766},
  doi = {10.3390/rs11151766},
  abstract = {Active satellite remote sensors have emerged in the last years in the field of archaeology, providing new tools for monitoring extensive cultural heritage landscapes and areas. These active sensors, namely synthetic aperture radar (SAR) satellites, provide systematic datasets for mapping land movements triggered from earthquakes, landslides, and so on. Copernicus, the European program for monitoring the environment, provides continuous radar datasets through the Sentinel-1 mission with an almost worldwide coverage. This paper aims to demonstrate how the use of open-access and freely distributed datasets such as those under the Copernicus umbrella, along with the exploitation of open-source radar processing software, namely the sentinel applications platform (SNAP) and SNAPHU tools, provided respectively by the European Space Agency (ESA) and the University of Stanford, can be used to extract an SAR interferogram in the wider area of Paphos, located in the western part of Cyprus. The city includes various heritage sites and monuments, some of them already included in the UNESCO World Heritage list. The interferogram was prepared to study the effects of an earthquake to the buildings and sites of the area. The earthquake of a 5.6 magnitude on the Richter scale was triggered on 15 April 2015 and was strongly felt throughout the whole island. The interferogram results were based on Differential Synthetic Aperture Radar Interferometry (D-InSAR) methodology, finding a maximum uplift of 74 mm and a maximum subsidence of 31 mm. The overall process and methodology are presented in this paper.},
  language = {en},
  number = {15},
  urldate = {2020-12-03},
  journal = {Remote Sensing},
  author = {Tzouvaras, M. and Kouhartsiouk, D. and Agapiou, A. and Danezis, C. and Hadjimitsis, D. G.},
  month = {January},
  year = {2019},
  publisher = {Multidisciplinary Digital Publishing Institute},
  keywords = {Copernicus, cultural heritage, Cyprus, decision-making, land movements, policy, SAR interferometry, Sentinel-1},
  pages = {1766},
  verba = {2.2.7}
  }

• C. Danezis, M. Chatzinikos, and C. Kotsakis. Linear and Nonlinear Deformation Effects in the Permanent GNSS Network of Cyprus. In 4th Joint International Symposium on Deformation Monitoring (JISDM 2019), Athens, Greece, May 2019. FIG, IAG, ISPRS.
  [BibTeX] [Abstract]
  

  Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.

  @inproceedings{danezis_jisdm_2019,
  title={{Linear} and {Nonlinear} {Deformation} {Effects} in the {Permanent} {GNSS} {Network} of {Cyprus}},
  author={Danezis, C. and Chatzinikos, M. and Kotsakis, C.},
  abstract = {Permanent Global Navigation Satellite Systems (GNSS) reference stations are well established as a powerful tool for the estimation of deformation induced by man-made or physical processes. GNSS sensors are successfully used to determine positions and velocities over a specified time period, with unprecedented accuracy, promoting research in many safety-critical areas, such as geophysics and geo-tectonics, tackling problems that torment traditional equipment and providing deformation products with absolute accuracy. Cyprus, being located at the Mediterranean fault, exhibits a very interesting geodynamic regime, which has yet to be investigated thoroughly. Accordingly, this research revolves around the estimation of crustal deformation in Cyprus using GNSS receivers. CYPOS (CYprus POsitioning System), a network of seven permanent GNSS stations has been operating since 2008, under the responsibility of the Department of Lands and Surveys. The continuous flow of positioning data collected over this network, offers the required information to investigate the behavior of the crustal deformation field of Cyprus using GNSS sensors for the first time. This paper presents the results of a multi-year analysis (11/2011–01/2017) of daily GNSS data and provides inferences of linear and nonlinear deforming signals into the position time series of the network stations. Specifically, 3D station velocities and seasonal periodic displacements are jointly estimated and presented via a data stacking approach with respect to the IGb08 reference frame.},
  booktitle={4th {Joint} {International} {Symposium} on {Deformation} {Monitoring} ({JISDM} 2019)},
  year={2019},
  month = {May},
  address = {Athens, Greece},
  organization={FIG, IAG, ISPRS}
  }

• C. Danezis, D. G. Hadjimitsis, M. Eineder, R. Brcic, A. Agapiou, K. Themistocleous, and others. CyCLOPS: a Novel Strategic Research Infrastructure Unit for Continuous Integrated Space-based Monitoring of Geohazards. In 4th Joint International Symposium on Deformation Monitoring (JISDM 2019), Athens, Greece, May 2019. FIG, IAG, ISPRS.
  [BibTeX] [Abstract]
  

  Cyprus, being located on the Mediterranean fault zone, exhibits a unique geodynamic regime since its tectonic evolution is driven by the interaction of the Eurasian and the African plate. Besides its seismological interest, Cyprus exhibits many active landslides and slope instabilities in areas of steep topography that pose an imminent threat for entire settlements, critical infrastructure, and cultural and natural heritage landmarks. To address these challenges, a novel strategic research infrastructure unit, abbreviated CyCLOPS, is being developed and established by Cyprus University of Technology in cooperation with the German Aerospace Agency (DLR). CyCLOPS will utilize novel space technologies, including cutting-edge European space missions, such as Galileo, Copernicus Sentinel and TerraSAR-X along with state-of-the-art processing techniques to monitor the effects of geohazards, such as earthquakes and landslides, and assess their impact on the built environment and cultural heritage landmarks. The latter will be achieved by the robust and continuous estimation of ground deformation and its velocity gradients at a national and regional level. The determination of deformation will be carried out by means of novel integrated GPS/GNSS and SAR techniques, rendering Cyprus a dedicated calibration and validation site for European space missions.

  @inproceedings{danezis_cyclops_jisdm_2019,
  title={{CyCLOPS}: A {Novel} {Strategic} {Research} {Infrastructure} {Unit} for {Continuous} {Integrated} {Space-based} {Monitoring} of {G}eohazards},
  author={Danezis, C. and Hadjimitsis, D. G. and Eineder, M. and Brcic, R. and Agapiou, A. and Themistocleous, K. and others},
  abstract = {Cyprus, being located on the Mediterranean fault zone, exhibits a unique geodynamic regime since its tectonic evolution is driven by the interaction of the Eurasian and the African plate. Besides its seismological interest, Cyprus exhibits many active landslides and slope instabilities in areas of steep topography that pose an imminent threat for entire settlements, critical infrastructure, and cultural and natural heritage landmarks. To address these challenges, a novel strategic research infrastructure unit, abbreviated CyCLOPS, is being developed and established by Cyprus University of Technology in cooperation with the German Aerospace Agency (DLR). CyCLOPS will utilize novel space technologies, including cutting-edge European space missions, such as Galileo, Copernicus Sentinel and TerraSAR-X along with state-of-the-art processing techniques to monitor the effects of geohazards, such as earthquakes and landslides, and assess their impact on the built environment and cultural heritage landmarks. The latter will be achieved by the robust and continuous estimation of ground deformation and its velocity gradients at a national and regional level. The determination of deformation will be carried out by means of novel integrated GPS/GNSS and SAR techniques, rendering Cyprus a dedicated calibration and validation site for European space missions.},
  booktitle={4th {Joint} {International} {Symposium} on {Deformation} {Monitoring} ({JISDM} 2019)},
  year={2019},
  month = {May},
  address = {Athens, Greece},
  organization={FIG, IAG, ISPRS}
  }

• K. Themistocleous, C. Danezis, and V. Gikas. Monitoring Ground Deformation of Cultural Heritage Sites using SAR and Geodetic Techniques: The Case Study of Choirokoitia, Cyprus. In 4th Joint International Symposium on Deformation Monitoring (JISDM 2019), Athens, Greece, May 2019. FIG, IAG, ISPRS.
  [BibTeX] [Abstract]
  

  Nowadays, assessing geo-hazards in cultural heritage sites in most cases takes place after the hazard has occurred. Monitoring structural and ground deformation resulting from geo-hazards facilitates the early recognition of potential risks and encourages effective conservation planning. This paper presents an integrated ground deformation monitoring approach based on the combined use of satellite SAR data, campaign-based GPS/GNSS observations, and aerial images from UAVs within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia is one of the most important prehistoric sites in the Eastern Mediterranean. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. As part of the PROTHEGO project, a series of field measurements were collected at the Choirokoitia site and compared against satellite SAR data to verify kinematic behavior of the broader area and to assist in monitoring potential geo-hazards over time. The results obtained indicate displacement rates of the order of 0.03 m/year. These results indicate that ground deformation should be monitored in the area surrounding the Choirokoitia using long-term, low-impact monitoring systems such as SAR images and UAV-based and geodetic techniques. The combination of such monitoring technologies can be compared to monitor and assess potential geo-hazards on archeological sites with increased accuracy.

  @inproceedings{themistocleous_jisdm_2019,
  title={Monitoring {G}round {D}eformation of {C}ultural {H}eritage {S}ites using {SAR} and {G}eodetic {T}echniques: {T}he {C}ase {S}tudy of {Choirokoitia}, {Cyprus}},
  author={Themistocleous, K. and Danezis, C. and Gikas, V.},
  abstract = {Nowadays, assessing geo-hazards in cultural heritage sites in most cases takes place after the hazard has occurred. Monitoring structural and ground deformation resulting from geo-hazards facilitates the early recognition of potential risks and encourages effective conservation planning. This paper presents an integrated ground deformation monitoring approach based on the combined use of satellite SAR data, campaign-based GPS/GNSS observations, and aerial images from UAVs within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia is one of the most important prehistoric sites in the Eastern Mediterranean. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. As part of the PROTHEGO project, a series of field measurements were collected at the Choirokoitia site and compared against satellite SAR data to verify kinematic behavior of the broader area and to assist in monitoring potential geo-hazards over time. The results obtained indicate displacement rates of the order of 0.03 m/year. These results indicate that ground deformation should be monitored in the area surrounding the Choirokoitia using long-term, low-impact monitoring systems such as SAR images and UAV-based and geodetic techniques. The combination of such monitoring technologies can be compared to monitor and assess potential geo-hazards on archeological sites with increased accuracy.},
  booktitle={4th {Joint} {International} {Symposium} on {Deformation} {Monitoring} ({JISDM} 2019)},
  year={2019},
  month = {May},
  address = {Athens, Greece},
  organization={FIG, IAG, ISPRS}
  }

• C. Danezis, D. Hadjimitsis, M. Eineder, R. Brcic, K. Themistocleous, C. Papoutsa, E. Mendonidis, M. Nikolaidis, M. Tzouvaras, and A. Christofe. Establishing a Strategic Research Infrastructure Unit to Monitor Natural Hazards in the Eastern Mediterranean Region via Integration of Space-based Techniques: The case of CyCLOPS. In 39th earsel symposium, Salzburg, Austria, July 2019.
  [BibTeX] [Abstract] [Download PDF]
  

  The Cyprus Continuously Operating Natural Hazards Monitoring and Prevention System, abbreviated CyCLOPS, is a research project funded by the European Regional and Development Fund, the Republic of Cyprus and the Research Promotion Foundation in the framework of the RESTART 2016 – 2020 programme under the grant agreement RPF/INFRASTRUCTURES/1216/0050. The project consortium is comprised by the Cyprus University of Technology and the German Aerospace Center (DLR) and has the support of the Department of Lands and Surveys (DLS) and the Geology Survey Department (DSG). The main objective of CyCLOPS is to found and maintain a novel integrated strategic research infrastructure (SRI) unit for solid earth processes and natural hazards monitoring in Cyprus and the Eastern Mediterranean region. This objective will be achieved by means of the establishment of a novel deformation monitoring and analysis infrastructure; the development of a state-of-the-art early warning system based on the integration of space-based derivatives and novel geospatial information and communication (ICT) infrastructure. The later will be realised via the establishment of strong international partnerships and essential synergies with the local stakeholders. The incentive for this research derives from the unique geodynamic and geotechnical regime of Cyprus, which is attributed to its geographic location, geology and weather. Initially, the unit will focus on earthquakes, and landslides. CyCLOPS will fill the lack of a dedicated, continuously operating system for monitoring these geohazards, and will augment and co-operate with existing infrastructure, such as the Tier-3 GNSS CORS Network of Cyprus (CYPOS) and the national seismological network operated by DSG. Furthermore, CyCLOPS will promote the use of modern Earth Observation (EO) constellations, such as Sentinel-1, COSMO SkyMed and TerraSAR-X, which is limited and has yet to be fully exploited in Cyprus by means of national-wide products, and in terms of the accuracy of the deformation output. CyCLOPS will consist of two main components (see Figure 1); a novel multiparametric network (MPN) of sensors, and the operation center (OC). The MPN will, in-turn, consist of two segments; the permanent and the mobile segment. The permanent segment will include cutting-edge Tier-1 high-rate permanent GNSS receivers, established at specific sites, on top of highly stable monuments (made of concrete or steel) attached to bedrock, and hence being fully aligned with IGS and EPN guidelines. These stations will co-locate with specifically designed SAR corner reflectors along with a multitude of sensors, such as weather stations, tiltmeters and in most cases with seismographs of the national seismological network. In this way, estimation of ground deformation and velocity will take place on a continuous basis by means of an integrated processing chain utilizing data from all the aforementioned sensors. Furthermore, CyCLOPS will exploit the latest European space missions, i.e. Galileo and Copernicus programs. The co-located configuration of permanent receivers and corner reflectors will be established and installed in such way as to be compliant with (a) all current GNSS constellations (GPS, GLONASS, Galileo, BeiDou) and (b) the Copernicus Sentinel-1 and the TerraSAR-X EO SAR sensors. The design, installation and calibration of the system will be carried out in close cooperation with the German Aerospace Center (DLR). The mobile segment will consist of the same grade of GPS/GNSS receivers along with airborne and terrestrial mapping sensors, such as UAS and laser scanners. Finally, the OC will handle the management, processing and storage of the incoming information. It will be comprised of three components; (a) the processing server, which will perform intensive GNSS/SAR processing and calibration operations, (b) the storage server, which will handle the storage of the raw observations and imagery along with auxiliary data required in the processing cycle (i.e. IGS precise products, atmospheric models etc.) and (c) the management server, which will include all the network configuration and control activities, and will host real time services, such as GIS services, Atmospheric Monitoring, and Episodic Event notification modules. Through this system and its unique co-located configuration (array of corner reflectors and GPS/GNSS CORS), Cyprus will be rendered a dedicated calibration site for present and future EO Space missions, within a framework fully compliant with European and National priority axes, thereby promoting civil protection and public safety in the south-eastern Mediterranean region.

  @inproceedings{danezis2019earsel,
  title = {Establishing a {S}trategic {R}esearch {I}nfrastructure {U}nit to {M}onitor {N}atural {H}azards in the {E}astern {M}editerranean {R}egion via {I}ntegration of {S}pace-based {T}echniques: {T}he case of {CyCLOPS}},
  url = {http://adsabs.harvard.edu/abs/2020EGUGA..2210582P},
  abstract = {The Cyprus Continuously Operating Natural Hazards Monitoring and Prevention System, abbreviated CyCLOPS, is a research project funded by the European Regional and Development Fund, the Republic of Cyprus and the Research Promotion Foundation in the framework of the RESTART 2016 – 2020 programme under the grant agreement RPF/INFRASTRUCTURES/1216/0050. The project consortium is comprised by the Cyprus University of Technology and the German Aerospace Center (DLR) and has the support of the Department of Lands and Surveys (DLS) and the Geology Survey Department (DSG). The main objective of CyCLOPS is to found and maintain a novel integrated strategic research infrastructure (SRI) unit for solid earth processes and natural hazards monitoring in Cyprus and the Eastern Mediterranean region. This objective will be achieved by means of the establishment of a novel deformation monitoring and analysis infrastructure; the development of a state-of-the-art early warning system based on the integration of space-based derivatives and novel geospatial information and communication (ICT) infrastructure. The later will be realised via the establishment of strong international partnerships and essential synergies with the local stakeholders. The incentive for this research derives from the unique geodynamic and geotechnical regime of Cyprus, which is attributed to its geographic location, geology and weather. Initially, the unit will focus on earthquakes, and landslides. CyCLOPS will fill the lack of a dedicated, continuously operating system for monitoring these geohazards, and will augment and co-operate with existing infrastructure, such as the Tier-3 GNSS CORS Network of Cyprus (CYPOS) and the national seismological network operated by DSG. Furthermore, CyCLOPS will promote the use of modern Earth Observation (EO) constellations, such as Sentinel-1, COSMO SkyMed and TerraSAR-X, which is limited and has yet to be fully exploited in Cyprus by means of national-wide products, and in terms of the accuracy of the deformation output. CyCLOPS will consist of two main components (see Figure 1); a novel multiparametric network (MPN) of sensors, and the operation center (OC). The MPN will, in-turn, consist of two segments; the permanent and the mobile segment. The permanent segment will include cutting-edge Tier-1 high-rate permanent GNSS receivers, established at specific sites, on top of highly stable monuments (made of concrete or steel) attached to bedrock, and hence being fully aligned with IGS and EPN guidelines. These stations will co-locate with specifically designed SAR corner reflectors along with a multitude of sensors, such as weather stations, tiltmeters and in most cases with seismographs of the national seismological network. In this way, estimation of ground deformation and velocity will take place on a continuous basis by means of an integrated processing chain utilizing data from all the aforementioned sensors. Furthermore, CyCLOPS will exploit the latest European space missions, i.e. Galileo and Copernicus programs. The co-located configuration of permanent receivers and corner reflectors will be established and installed in such way as to be compliant with (a) all current GNSS constellations (GPS, GLONASS, Galileo, BeiDou) and (b) the Copernicus Sentinel-1 and the TerraSAR-X EO SAR sensors. The design, installation and calibration of the system will be carried out in close cooperation with the German Aerospace Center (DLR). The mobile segment will consist of the same grade of GPS/GNSS receivers along with airborne and terrestrial mapping sensors, such as UAS and laser scanners. Finally, the OC will handle the management, processing and storage of the incoming information. It will be comprised of three components; (a) the processing server, which will perform intensive GNSS/SAR processing and calibration operations, (b) the storage server, which will handle the storage of the raw observations and imagery along with auxiliary data required in the processing cycle (i.e. IGS precise products, atmospheric models etc.) and (c) the management server, which will include all the network configuration and control activities, and will host real time services, such as GIS services, Atmospheric Monitoring, and Episodic Event notification modules. Through this system and its unique co-located configuration (array of corner reflectors and GPS/GNSS CORS), Cyprus will be rendered a dedicated calibration site for present and future EO Space missions, within a framework fully compliant with European and National priority axes, thereby promoting civil protection and public safety in the south-eastern Mediterranean region.},
  urldate = {2020-12-03},
  author = {Danezis, C. and Hadjimitsis, D. and Eineder, M. and Brcic, R. and Themistocleous, K. and Papoutsa, C. and Mendonidis, E. and Nikolaidis, M. and Tzouvaras, M. and Christofe, A.},
  month = {July},
  year = {2019},
  booktitle = {39th EARSeL Symposium},
  address = {Salzburg, Austria}
  }

• C. Danezis, D. G. Hadjimitsis, M. Eineder, R. Brcic, K. Themistocleous, C. Papoutsa, M. Tzouvaras, and M. Nikolaidis. CyCLOPS: the Formation of a Strategic Research Infrastructure Unit for Space-based Monitoring of Geohazards and Critical Infrastructure in the Southeastern Mediterranean Region. In Infrastructures Planning and Monitoring User Consultation Conference 2019, Frascati, Italy, February 2019. European space agency.
  [BibTeX] [Abstract] [Download PDF]
  

  The Cyprus Continuously Operating Natural Hazards Monitoring and Prevention System, abbreviated CyCLOPS, is a research project funded by the European Regional Development Fund, the Republic of Cyprus and the Research Promotion Foundation in the framework of the RESTART 2016 – 2020 programme under the grant agreement INFRASTRUCTURES/1216/0050. The project consortium is formed by the Cyprus University of Technology and the German Aerospace Center (DLR) and is further promoted by major local supporters/ stakeholders, such as the Department of Lands and Surveys (DLS), the Geological Survey Department (GSD) and the Electricity Authority of Cyprus (EAC). The mission of CyCLOPS is to establish and maintain a novel strategic research infrastructure (SRI) unit for monitoring natural hazards in Cyprus and the broader EMMENA region. Due to its unique geodynamic and geotechnical regime, Cyprus exhibits a significant number of earthquakes, active landslides and land instabilities that affect the built environment and cultural – natural heritage landmarks. To date, the combined result of geohazards has led to the abandonment of 8 villages, and the destruction of numerous properties and critical infrastructure (i.e. roads and utility networks). Since current monitoring infrastructure is limited to traditional equipment, no thorough research has been carried out to determine ground deformation accurately and at dense spatial resolution. Nevertheless, the emergence of new Earth Observation monitoring techniques provided additional and effective tools to enhance preparedness with respect to the occurrence of geohazards. This was the main incentive behind CyCLOPS. A continuously operating system that will incorporate the use of EO technologies in the civil protection strategy and augment existing infrastructure operated by national stakeholders. CyCLOPS will make use of two of the most prominent space technologies, namely, Global Navigation Satellite Systems (GNSS) and Synthetic Aperture Radar (SAR) missions in a novel integrated scheme. The system will consist of two main components; a multiparametric network (MPN) of sensors and an Operation Center (OC). The MPN will consist of state-of-the-art, high-rate, Tier-1 GNSS reference stations (CORS), established at selected sites according to the International GNSS Service (IGS) and the European Permanent Network (EPN) specifications. These stations will co-locate with specifically designed SAR Corner Reflectors (CRs) along with numerous heterogeneous sensors, such as weather stations, tiltmeters and seismographs of the national seismological network. CyCLOPS will support the latest European Space missions, namely, Galileo, Copernicus Sentinel-1 and TerraSAR-X EO SAR sensors. The co-located configuration of GNSS and SAR CRs will provide deformation products at the centimeter accuracy by means of a least-squares calibration process. Finally, the OC will host a multitude of services, such as an atmospheric monitoring web service, a GIS web platform to promote the exchange of useful data, and a sophisticated episodic event notification module to enable efficient warning to all involved parties in order to enhance public safety and protect critical infrastructure. In this scheme, Cyprus will become a dedicated calibration site for current and future space missions, within a framework in line with the European and national priority axes.

  @inproceedings{danezis_frascati_2019,
  title = {{CyCLOPS}: The {F}ormation of a {S}trategic {R}esearch {I}nfrastructure {U}nit for {S}pace-based {M}onitoring of {G}eohazards and {C}ritical {I}nfrastructure in the {S}outheastern {M}editerranean {R}egion},
  url = {http://infrastructures2019.esa.int/index.php},
  abstract = {The Cyprus Continuously Operating Natural Hazards Monitoring and Prevention System, abbreviated CyCLOPS, is a research project funded by the European Regional Development Fund, the Republic of Cyprus and the Research Promotion Foundation in the framework of the RESTART 2016 – 2020 programme under the grant agreement INFRASTRUCTURES/1216/0050. The project consortium is formed by the Cyprus University of Technology and the German Aerospace Center (DLR) and is further promoted by major local supporters/ stakeholders, such as the Department of Lands and Surveys (DLS), the Geological Survey Department (GSD) and the Electricity Authority of Cyprus (EAC). The mission of CyCLOPS is to establish and maintain a novel strategic research infrastructure (SRI) unit for monitoring natural hazards in Cyprus and the broader EMMENA region. Due to its unique geodynamic and geotechnical regime, Cyprus exhibits a significant number of earthquakes, active landslides and land instabilities that affect the built environment and cultural - natural heritage landmarks. To date, the combined result of geohazards has led to the abandonment of 8 villages, and the destruction of numerous properties and critical infrastructure (i.e. roads and utility networks). Since current monitoring infrastructure is limited to traditional equipment, no thorough research has been carried out to determine ground deformation accurately and at dense spatial resolution. Nevertheless, the emergence of new Earth Observation monitoring techniques provided additional and effective tools to enhance preparedness with respect to the occurrence of geohazards. This was the main incentive behind CyCLOPS. A continuously operating system that will incorporate the use of EO technologies in the civil protection strategy and augment existing infrastructure operated by national stakeholders. CyCLOPS will make use of two of the most prominent space technologies, namely, Global Navigation Satellite Systems (GNSS) and Synthetic Aperture Radar (SAR) missions in a novel integrated scheme. The system will consist of two main components; a multiparametric network (MPN) of sensors and an Operation Center (OC). The MPN will consist of state-of-the-art, high-rate, Tier-1 GNSS reference stations (CORS), established at selected sites according to the International GNSS Service (IGS) and the European Permanent Network (EPN) specifications. These stations will co-locate with specifically designed SAR Corner Reflectors (CRs) along with numerous heterogeneous sensors, such as weather stations, tiltmeters and seismographs of the national seismological network. CyCLOPS will support the latest European Space missions, namely, Galileo, Copernicus Sentinel-1 and TerraSAR-X EO SAR sensors. The co-located configuration of GNSS and SAR CRs will provide deformation products at the centimeter accuracy by means of a least-squares calibration process. Finally, the OC will host a multitude of services, such as an atmospheric monitoring web service, a GIS web platform to promote the exchange of useful data, and a sophisticated episodic event notification module to enable efficient warning to all involved parties in order to enhance public safety and protect critical infrastructure. In this scheme, Cyprus will become a dedicated calibration site for current and future space missions, within a framework in line with the European and national priority axes.},
  author = {Danezis, C. and Hadjimitsis, D. G. and Eineder, M. and Brcic, R. and Themistocleous, K. and Papoutsa, C. and Tzouvaras, M. and Nikolaidis, M.},
  address = {Frascati, Italy},
  month = {February},
  year = {2019},
  publisher = {European Space Agency},
  booktitle = {Infrastructures {Planning} and {Monitoring} {User} {Consultation} {Conference} 2019}
  }

• C. Danezis. CyCLOPS: Integrated Space-based Monitoring of Geohazards and Augmentation of National GNSS Infrastructure. In Unmanned Airborne Systems in Surveying Engineering, Platres, Cyprus, April 2019. Cyprus Association of Rural & Surveying Engineers.
  [BibTeX]

  @inproceedings{danezis_cyarse_2019,
  type = {Invited {Speaker}},
  author = {Danezis, C.},
  title = {{CyCLOPS}: {Integrated} {Space-based} {Monitoring} of {Geohazards} and {Augmentation} of {National} {GNSS} {Infrastructure}},
  publisher = {Cyprus {Association} of {Rural} \& {Surveying} {Engineers}},
  booktitle = {{Unmanned} {Airborne} {Systems} in {Surveying} {Engineering}},
  address = {Platres, Cyprus},
  month = {April},
  year = {2019}
  }

2018

• Y. Vacanas and C. Danezis. An Overview of the Risk of Delay in Cyprus Construction Industry. International Journal of Construction Management, page 1–13, November 2018. doi:10.1080/15623599.2018.1541703
  [BibTeX] [Abstract] [Download PDF]
  

  This article determines the main issues related to delay in construction projects in Cyprus. Initially, a detailed comparative review was carried out to identify the most significant causes of delay at the international level. Based on the latter and the opinions of distinguished members of the industry, a survey questionnaire was designed and distributed to a total number of 242 members of the Cyprus Scientific and Technical Chamber. The analysis of the results obtained by 54 respondents indicated particular common-practice issues that affect completion in construction projects in Cyprus, such as duration of delays, Extension of time (EOT) awards and agreements, recording methods and programmes of works. Ultimately, by using the importance of delay causes as perceived by the respondents it was determined that in Cyprus construction industry ‘variations requested by the client’ (70\%), ‘mistakes and missing information from consultants’ drawings’ (55\%), ‘low productivity’ (55\%), ‘difficulties in financing of the works by the contractor’ (52\%) and ‘inadequate programming of works’ (50\%) to be the main causes of delay in Cyprus. Based on the results, specific practices are recommended for the control of delay in the completion of construction projects.

  @article{vacanas_overview_2018,
  title = {An {O}verview of the {R}isk of {D}elay in {Cyprus} {C}onstruction {I}ndustry},
  volume = {0},
  issn = {1562-3599},
  url = {https://doi.org/10.1080/15623599.2018.1541703},
  doi = {10.1080/15623599.2018.1541703},
  abstract = {This article determines the main issues related to delay in construction projects in Cyprus. Initially, a detailed comparative review was carried out to identify the most significant causes of delay at the international level. Based on the latter and the opinions of distinguished members of the industry, a survey questionnaire was designed and distributed to a total number of 242 members of the Cyprus Scientific and Technical Chamber. The analysis of the results obtained by 54 respondents indicated particular common-practice issues that affect completion in construction projects in Cyprus, such as duration of delays, Extension of time (EOT) awards and agreements, recording methods and programmes of works. Ultimately, by using the importance of delay causes as perceived by the respondents it was determined that in Cyprus construction industry ‘variations requested by the client’ (70\%), ‘mistakes and missing information from consultants’ drawings’ (55\%), ‘low productivity’ (55\%), ‘difficulties in financing of the works by the contractor’ (52\%) and ‘inadequate programming of works’ (50\%) to be the main causes of delay in Cyprus. Based on the results, specific practices are recommended for the control of delay in the completion of construction projects.},
  number = {0},
  urldate = {2019-06-19},
  journal = {International {Journal} of {Construction} {Management}},
  author = {Vacanas, Y. and Danezis, C.},
  month = {November},
  year = {2018},
  publisher = {Taylor \& Francis},
  keywords = {Causes, Construction, Cyprus, Delay, Project Management},
  pages = {1--13},
  verba = {2.2.6}
  }

• D. G. Hadjimitsis, K. Themistocleous, S. Evagorou E.and Michaelides, A. Christofe, A. Nisantzi, K. Neocleous, C. Papoutsa, C. Mettas, M. Tzouvaras, E. Loulli, G. Kouta, C. Danezis, R. Lasaponara, N. Masini, D. Cerra, G. Schreier, and G. Papadavid. Capitalize on the Experience of the ATHENA Project for Cultural Heritage for the Eratosthenes Centre of Excellence for the Benefit of the East Med Region. In Marinos Ioannides, Eleanor Fink, Raffaella Brumana, Petros Patias, Anastasios Doulamis, João Martins, and Manolis Wallace, editors, Euromed 2018: Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and Protection, Lecture {Notes} in {Computer} {Science}, page 639–647. Springer international publishing, 2018.
  [BibTeX] [Abstract]
  

  The “ATHENA” H2020 Twinning project seeks to establish a Center of Excellence in the field of Remote Sensing for Cultural Heritage through the development of an enhanced knowledge base and innovative methods in the areas of Archaeology and Cultural Heritage. This paper presents an overview of the ATHENA twinning project as well a review of the remote sensing in archaeology. The ATHENA stakeholder hub is presented through a WEBGIS platform. The importance of capitalizing on the experience of running the ATHENA project for the benefit of the ERATOSTHENES Centre of Excellence (ECoE) is explained. In recent years, Earth Observation (EO) techniques have been used extensively for archaeological and cultural heritage applications, which makes the ECoE a key player in EO activities in the Eastern Meditteranean region. The different areas that are under the umbrella of the remote sensing in archaeology sector are categorized based on the review findings. Finally, how Earth observation and remote sensing is spread out through research activities in the Eastern Meditteranean region from 1998 to 2018 is presented based on the Scopus engine.

  @inproceedings{hadjimitsis_capitalize_2018,
  series = {Lecture {Notes} in {Computer} {Science}},
  title = {Capitalize on the {Experience} of the {ATHENA} {Project} for {Cultural} {Heritage} for the {Eratosthenes} {Centre} of {Excellence} for the {Benefit} of the {East} {Med} {Region}},
  isbn = {978-3-030-01762-0},
  abstract = {The “ATHENA” H2020 Twinning project seeks to establish a Center of Excellence in the field of Remote Sensing for Cultural Heritage through the development of an enhanced knowledge base and innovative methods in the areas of Archaeology and Cultural Heritage. This paper presents an overview of the ATHENA twinning project as well a review of the remote sensing in archaeology. The ATHENA stakeholder hub is presented through a WEBGIS platform. The importance of capitalizing on the experience of running the ATHENA project for the benefit of the ERATOSTHENES Centre of Excellence (ECoE) is explained. In recent years, Earth Observation (EO) techniques have been used extensively for archaeological and cultural heritage applications, which makes the ECoE a key player in EO activities in the Eastern Meditteranean region. The different areas that are under the umbrella of the remote sensing in archaeology sector are categorized based on the review findings. Finally, how Earth observation and remote sensing is spread out through research activities in the Eastern Meditteranean region from 1998 to 2018 is presented based on the Scopus engine.},
  language = {en},
  booktitle = {EuroMed 2018: {D}igital {Heritage}. {Progress} in {Cultural} {Heritage}: {Documentation}, {Preservation}, and {Protection}},
  publisher = {Springer International Publishing},
  author = {Hadjimitsis, D. G. and Themistocleous, K. and Evagorou, E.and Michaelides, S. and Christofe, A. and Nisantzi, A. and Neocleous, K. and Papoutsa, C. and Mettas, C. and Tzouvaras, M. and Loulli, E. and Kouta, G. and Danezis, C. and Lasaponara, R. and Masini, N. and Cerra, D. and Schreier, G. and Papadavid, G.},
  editor = {Ioannides, Marinos and Fink, Eleanor and Brumana, Raffaella and Patias, Petros and Doulamis, Anastasios and Martins, João and Wallace, Manolis},
  year = {2018},
  keywords = {Athena centre for cultural heritage, Copernicus, ECoE, Excelsior, Remote sensing},
  pages = {639--647}
  }

• K. Themistocleous and C. Danezis. Monitoring Cultural Heritage Sites Affected by Geohazards. In Earth Resources and Environmental Remote Sensing/GIS Applications IX, volume 10790, page 1079009. International society for optics and photonics (spie), October 2018. doi:10.1117/12.2325455
  [BibTeX] [Abstract] [Download PDF]
  

  Currently, assessing geo-hazards in cultural heritage sites takes place after the geo-hazard has occurred. The long-term vulnerability of cultural heritage is commonly focused on the site itself, in response to environmental risks, without fully considering or understanding the entire geological and geotechnical context. However, the high costs of maintenance of cultural heritage sites directly enforce the prioritisation of the monitoring and conservation policies to ensure sustainable conservation. Monitoring the deformation of structures as well as their surroundings facilitates the early recognition of potential risks and enables effective conservation planning. This paper will present the results of the case study of the UNESCO World Heritage Site of Choirokoitia, Cyprus, where long-term low-impact monitoring systems such as UAVs and geodetic techniques were used to monitor and assess the risk from natural hazards on the archaeological site to evaluate potential geo-hazards.

  @inproceedings{themistocleous_monitoring_2018,
  title = {Monitoring {C}ultural {H}eritage {S}ites {A}ffected by {G}eohazards},
  volume = {10790},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10790/1079009/Monitoring-cultural-heritage-sites-affected-by-geohazards/10.1117/12.2325455.short},
  doi = {10.1117/12.2325455},
  abstract = {Currently, assessing geo-hazards in cultural heritage sites takes place after the geo-hazard has occurred. The long-term vulnerability of cultural heritage is commonly focused on the site itself, in response to environmental risks, without fully considering or understanding the entire geological and geotechnical context. However, the high costs of maintenance of cultural heritage sites directly enforce the prioritisation of the monitoring and conservation policies to ensure sustainable conservation. Monitoring the deformation of structures as well as their surroundings facilitates the early recognition of potential risks and enables effective conservation planning. This paper will present the results of the case study of the UNESCO World Heritage Site of Choirokoitia, Cyprus, where long-term low-impact monitoring systems such as UAVs and geodetic techniques were used to monitor and assess the risk from natural hazards on the archaeological site to evaluate potential geo-hazards.},
  urldate = {2019-06-19},
  booktitle = {Earth {Resources} and {Environmental} {Remote} {Sensing}/{GIS} {Applications} {IX}},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Themistocleous, K. and Danezis, C.},
  month = {October},
  year = {2018},
  pages = {1079009}
  }

• K. Themistocleous, C. Danezis, P. Frattini, G. Crosta, and A. Valagussa. Best Practices for Monitoring, Mitigation, and Preservation of Cultural Heritage Sites Affected by Geohazards: The Results of the PROTHEGO Project. In Sixth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2018), volume 10773, page 107730Z. International society for optics and photonics, August 2018. doi:10.1117/12.2503915
  [BibTeX] [Abstract] [Download PDF]
  

  PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) utilized novel space technology to monitor surface deformation with mm precision to analyze the impact of geo-hazards in cultural heritage sites in Europe. The project, which took place over 30 months, included the 395 monuments of UNESCO in Europe to monitor geo-hazards, with case studies conducted in 4 UNESCO sites in England, Spain, Italy and Cyprus. The PROTHEGO project used long-term low-impact monitoring systems, such as UAVs and geodetic techniques, as well as InSAR data to monitor and assess the risk from natural hazards on the archaeological site to evaluate potential geo-hazards. This paper will present an overview of best practices for the innovative diagnosis, monitoring, mitigation and preservation of Cultural Heritage monuments sites affected by geo-hazards that are potentially unstable due to landslides, sinkholes, settlement, subsidence, active tectonics as well as structural deformation, which are based on the results of the 4 case studies featured in the project. The “PROTection of European Cultural HEritage from GeO-hazards (PROTHEGO)” project HERITAGE PLUS/0314/36 is funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH) – HERITAGE PLUS under ERA‐NET Plus and the Seventh Framework Programme (FP7) of the European Commission and the Cyprus Research Promotion Foundation, contract KOINA/ΠΚΠ-HERITAGE PLUS/0314/36.

  @inproceedings{themistocleous_best_2018,
  title = {Best {P}ractices for {M}onitoring, {M}itigation, and {P}reservation of {C}ultural {H}eritage {S}ites {A}ffected by {G}eohazards: {T}he {R}esults of the {PROTHEGO} {P}roject},
  volume = {10773},
  shorttitle = {Best practices for monitoring, mitigation, and preservation of cultural heritage sites affected by geo-hazards},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10773/107730Z/Best-practices-for-monitoring-mitigation-and-preservation-of-cultural-heritage/10.1117/12.2503915.short},
  doi = {10.1117/12.2503915},
  abstract = {PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) utilized novel space technology to monitor surface deformation with mm precision to analyze the impact of geo-hazards in cultural heritage sites in Europe. The project, which took place over 30 months, included the 395 monuments of UNESCO in Europe to monitor geo-hazards, with case studies conducted in 4 UNESCO sites in England, Spain, Italy and Cyprus. The PROTHEGO project used long-term low-impact monitoring systems, such as UAVs and geodetic techniques, as well as InSAR data to monitor and assess the risk from natural hazards on the archaeological site to evaluate potential geo-hazards. This paper will present an overview of best practices for the innovative diagnosis, monitoring, mitigation and preservation of Cultural Heritage monuments sites affected by geo-hazards that are potentially unstable due to landslides, sinkholes, settlement, subsidence, active tectonics as well as structural deformation, which are based on the results of the 4 case studies featured in the project. The "PROTection of European Cultural HEritage from GeO-hazards (PROTHEGO)” project HERITAGE PLUS/0314/36 is funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH) – HERITAGE PLUS under ERA‐NET Plus and the Seventh Framework Programme (FP7) of the European Commission and the Cyprus Research Promotion Foundation, contract KOINA/ΠΚΠ-HERITAGE PLUS/0314/36.},
  urldate = {2018-11-05},
  booktitle = {Sixth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2018})},
  publisher = {International Society for Optics and Photonics},
  author = {Themistocleous, K. and Danezis, C. and Frattini, P. and Crosta, G. and Valagussa, A.},
  month = {August},
  year = {2018},
  pages = {107730Z}
  }

2017

• K. Themistocleous, C. Danezis, E. Mendonidis, and E. Lymperopoulou. Monitoring Ground Deformation of Cultural Heritage sites using UAVs and Geodetic Techniques: the Case Study of Choirokoitia, JPI PROTHEGO project. In Earth Resources and Environmental Remote Sensing/GIS Applications VIII, volume 10428, Warsaw, Poland, 2017. International society for optics and photonics. doi:doi: 10.1117/12.2279478
  [BibTeX] [Abstract] [Download PDF]
  

  This paper presents the integrated methods using UAVs and geodetic techniques to monitor ground deformation within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia, occupied from the 7th to the 4th millennium B.C., is one of the most important prehistoric sites in the eastern Mediterranean. The study is conducted under the PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) project, which is a collaborative research project funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH)-Heritage Plus in 2015-2018 (www.prothego.eu) and through the Cyprus Research Promotion Foundation. PROTHEGO aims to make an innovative contribution towards the analysis of geo-hazards in areas of cultural heritage, and uses novel space technology based on radar interferometry to retrieve information on ground stability and motion in the 400+ UNESCO’s World Heritage List monuments and sites of Europe. The field measurements collected at the Choirokoitia site will be later compared with SAR data to verify micro-movements in the area to monitor potential geo-hazards. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. © 2017 SPIE.

  @inproceedings{themistocleous_monitoring_2017,
  address = {Warsaw, Poland},
  title = {Monitoring {Ground} {Deformation} of {Cultural} {Heritage} sites using {UAVs} and {Geodetic} {Techniques}: the {Case} {Study} of {Choirokoitia}, {JPI} {PROTHEGO} project},
  volume = {10428},
  shorttitle = {Monitoring ground deformation of cultural heritage sites using {UAVs} and geodetic techniques},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10428/0000/Monitoring-ground-deformation-of-cultural-heritage-sites-using-UAVs-and/10.1117/12.2279478.short},
  doi = {doi: 10.1117/12.2279478},
  abstract = {This paper presents the integrated methods using UAVs and geodetic techniques to monitor ground deformation within the Choirokoitia UNESCO World Heritage Site in Cyprus. The Neolithic settlement of Choirokoitia, occupied from the 7th to the 4th millennium B.C., is one of the most important prehistoric sites in the eastern Mediterranean. The study is conducted under the PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) project, which is a collaborative research project funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH)-Heritage Plus in 2015-2018 (www.prothego.eu) and through the Cyprus Research Promotion Foundation. PROTHEGO aims to make an innovative contribution towards the analysis of geo-hazards in areas of cultural heritage, and uses novel space technology based on radar interferometry to retrieve information on ground stability and motion in the 400+ UNESCO's World Heritage List monuments and sites of Europe. The field measurements collected at the Choirokoitia site will be later compared with SAR data to verify micro-movements in the area to monitor potential geo-hazards. The site is located on a steep hill, which makes it vulnerable to rock falls and landslides. © 2017 SPIE.},
  urldate = {2017-09-19},
  booktitle = {Earth {Resources} and {Environmental} {Remote} {Sensing}/{GIS} {Applications} {VIII}},
  publisher = {International Society for Optics and Photonics},
  author = {Themistocleous, K. and Danezis, C. and Mendonidis, E. and Lymperopoulou, E.},
  year = {2017}
  }

• T. Lazarou and C. Danezis. Assessment of Modern Smartphone Sensors Performance on Vehicle Localization in Urban Environments. In Fifth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2017), volume 10444, page 104441S. International society for optics and photonics (spie), September 2017. doi:10.1117/12.2292354
  [BibTeX] [Abstract] [Download PDF]
  

  The advent of Global Navigation Satellite Systems (GNSS) initiated a revolution in Positioning, Navigation and Timing (PNT) applications. Besides the enormous impact on geospatial data acquisition and reality capture, satellite navigation has penetrated everyday life, a fact which is proved by the increasing degree of human reliance on GNSS-enabled smart devices to perform casual activities. Nevertheless, GNSS does not perform well in all cases. Specifically, in GNSS-challenging environments, such as urban canyons or forested areas, navigation performance may be significantly degraded or even nullified. Consequently, positioning is achieved by combining GNSS with additional heterogeneous information or sensors, such as inertial sensors. To date, most smartphones are equipped with at least accelerometers and gyroscopes, besides GNSS chipsets. In the frame of this research, difficult localization scenarios were investigated to assess the performance of these low-cost inertial sensors with respect to higher grade GNSS and IMU systems. Four state-of-the-art smartphones were mounted on a specifically designed on-purpose build platform along with reference equipment. The platform was installed on top of a vehicle, which was driven by a predefined trajectory that included several GNSS-challenging parts. Consequently, positioning and inertial readings were acquired by smartphones and compared to the information collected by the reference equipment. The results indicated that although the smartphone GNSS receivers have increased sensitivity, they were unable to produce an acceptable solution for more than 30\% of the driven course. However, all smartphones managed to identify, up to a satisfactory degree, distinct driving features, such as curves or bumps.

  @inproceedings{lazarou_assessment_rscy_2017,
  title = {Assessment of {M}odern {S}martphone {S}ensors {P}erformance on {V}ehicle {L}ocalization in {U}rban {E}nvironments},
  volume = {10444},
  url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10444/104441S/Assessment-of-modern-smartphone-sensors-performance-on-vehicle-localization-in/10.1117/12.2292354.short},
  doi = {10.1117/12.2292354},
  abstract = {The advent of Global Navigation Satellite Systems (GNSS) initiated a revolution in Positioning, Navigation and Timing (PNT) applications. Besides the enormous impact on geospatial data acquisition and reality capture, satellite navigation has penetrated everyday life, a fact which is proved by the increasing degree of human reliance on GNSS-enabled smart devices to perform casual activities. Nevertheless, GNSS does not perform well in all cases. Specifically, in GNSS-challenging environments, such as urban canyons or forested areas, navigation performance may be significantly degraded or even nullified. Consequently, positioning is achieved by combining GNSS with additional heterogeneous information or sensors, such as inertial sensors. To date, most smartphones are equipped with at least accelerometers and gyroscopes, besides GNSS chipsets. In the frame of this research, difficult localization scenarios were investigated to assess the performance of these low-cost inertial sensors with respect to higher grade GNSS and IMU systems. Four state-of-the-art smartphones were mounted on a specifically designed on-purpose build platform along with reference equipment. The platform was installed on top of a vehicle, which was driven by a predefined trajectory that included several GNSS-challenging parts. Consequently, positioning and inertial readings were acquired by smartphones and compared to the information collected by the reference equipment. The results indicated that although the smartphone GNSS receivers have increased sensitivity, they were unable to produce an acceptable solution for more than 30\% of the driven course. However, all smartphones managed to identify, up to a satisfactory degree, distinct driving features, such as curves or bumps.},
  urldate = {2018-11-05},
  booktitle = {Fifth {International} {Conference} on {Remote} {Sensing} and {Geoinformation} of the {Environment} ({RSCy2017})},
  publisher = {International Society for Optics and Photonics (SPIE)},
  author = {Lazarou, T. and Danezis, C.},
  month = {September},
  year = {2017},
  pages = {104441S}
  }

2016

• E. A. Tantele, R. A. Votsis, C. Danezis, C. Anastasiou, and N. Georgiou. Mapping the Variability of Carbonation Progress using GIS Techniques and Field Data: A Case Study of the Limassol District. Natural hazards, 83(1):183–199, October 2016. doi:10.1007/s11069-016-2509-4
  [BibTeX] [Abstract] [Download PDF]
  

  Carbonation-induced corrosion of the steel reinforcement is the major deterioration factor of the RC infrastructures in urban areas. Carbonation progress in concrete is influenced by the exposure and environmental conditions prevailing at each area. Therefore, the rate of deterioration due to carbonation varies at different areas. Field measurements can quantify this carbonation progress for specific structures and areas. However, the scattered nature of individual field data offers little information to be considered for the assessment of existing structures or the design of new structures. This study aims to bridge this gap and shows that individual field data can be combined to characterise an area using GIS mapping tools. A generated map can depict the variability of carbonation progress with the geographical location. Measurements of the carbonation depth of several buildings at different locations in the Limassol district have been provided by a construction laboratory. Such information can be used to depict the carbonation progress on each structure through the calculation of the carbonation factor and then portray its value using mapping techniques. The result is a corrosion risk map of the Limassol district depicting the variability of carbonation progress with geographical locations. This can be used by engineers and managing authorities as a prediction tool for the initiation of carbonation-induced corrosion in existing structures and also at design stage to set the durability requirements of the concrete cover depth.

  @article{tantele_mapping_2016,
  title = {Mapping the {Variability} of {Carbonation} {Progress} using {GIS} {Techniques} and {Field} {Data}: {A} {Case} {Study} of the {Limassol} {D}istrict},
  volume = {83},
  issn = {1573-0840},
  url = {https://doi.org/10.1007/s11069-016-2509-4},
  doi = {10.1007/s11069-016-2509-4},
  abstract = {Carbonation-induced corrosion of the steel reinforcement is the major deterioration factor of the RC infrastructures in urban areas. Carbonation progress in concrete is influenced by the exposure and environmental conditions prevailing at each area. Therefore, the rate of deterioration due to carbonation varies at different areas. Field measurements can quantify this carbonation progress for specific structures and areas. However, the scattered nature of individual field data offers little information to be considered for the assessment of existing structures or the design of new structures. This study aims to bridge this gap and shows that individual field data can be combined to characterise an area using GIS mapping tools. A generated map can depict the variability of carbonation progress with the geographical location. Measurements of the carbonation depth of several buildings at different locations in the Limassol district have been provided by a construction laboratory. Such information can be used to depict the carbonation progress on each structure through the calculation of the carbonation factor and then portray its value using mapping techniques. The result is a corrosion risk map of the Limassol district depicting the variability of carbonation progress with geographical locations. This can be used by engineers and managing authorities as a prediction tool for the initiation of carbonation-induced corrosion in existing structures and also at design stage to set the durability requirements of the concrete cover depth.},
  language = {en},
  number = {1},
  urldate = {2020-12-03},
  journal = {Natural Hazards},
  publisher = {},
  author = {Tantele, E.A. and Votsis, R. A. and Danezis, C. and Anastasiou, C. and Georgiou, N.},
  month = {October},
  year = {2016},
  pages = {183--199},
  verba = {2.2.5}
  }

• Y. Vacanas, K. Themistocleous, A. Agapiou, and C. Danezis. Contemporary Methodology for Infrastructure Project Management, Dispute Avoidance and Delay Analysis. Anales de edificación, 2(1):12, April 2016. 00000 doi:10.20868/ade.2016.3193
  [BibTeX] [Abstract] [Download PDF]
  

  The causes of disruption and delay to infrastructure construction projects are known but inevitable, and the current methods for delay analysis and dispute resolution are expensive and faced with suspiciousness. In this paper a contemporary methodology is proposed for efficient and transparent record keeping and sharing for effective project management, delay and dispute avoidance and cheaper dispute resolution. Modern technology tools (UAV images, Long-range 3D Laser scanning and BIM technologies can be used for data collection and 3D visual illustration of the milestone works progress; Time lapse camera images can provide visualisation of the daily progress of the works and indication of the conditions and presence of resources in any day; GNSS – Mobile technology can be used to pattern the machinery and human resources presence and motion on site; High resolution satellite images can give periodic images for the general progress of the works, RFID technology can be used for machinery and human resources monitoring and material quantities tracking and management) are utilized to provide important and useful information, both spatial and descriptive, to a Geographical Information System (GIS) central server, which in turn provides reports regarding milestone issues related to the project works.

  @article{vacanas_contemporary_2016,
  title = {Contemporary {Methodology} for {Infrastructure} {Project} {Management}, {Dispute} {Avoidance} and {Delay} {Analysis}},
  volume = {2},
  issn = {2444-1309},
  url = {http://polired.upm.es/index.php/anales_de_edificacion/article/view/3193},
  doi = {10.20868/ade.2016.3193},
  abstract = {The causes of disruption and delay to infrastructure construction projects are known but inevitable, and the current methods for delay analysis and dispute resolution are expensive and faced with suspiciousness. In this paper a contemporary methodology is proposed for efficient and transparent record keeping and sharing for effective project management, delay and dispute avoidance and cheaper dispute resolution. Modern technology tools (UAV images, Long-range 3D Laser scanning and BIM technologies can be used for data collection and 3D visual illustration of the milestone works progress; Time lapse camera images can provide visualisation of the daily progress of the works and indication of the conditions and presence of resources in any day; GNSS - Mobile technology can be used to pattern the machinery and human resources presence and motion on site; High resolution satellite images can give periodic images for the general progress of the works, RFID technology can be used for machinery and human resources monitoring and material quantities tracking and management) are utilized to provide important and useful information, both spatial and descriptive, to a Geographical Information System (GIS) central server, which in turn provides reports regarding milestone issues related to the project works.},
  number = {1},
  urldate = {2016-07-13},
  journal = {Anales de Edificación},
  author = {Vacanas, Y. and Themistocleous, K. and Agapiou, A. and Danezis, C.},
  month = {April},
  year = {2016},
  note = {00000},
  pages = {12},
  verba = {2.2.4}
  }

• A. Kealy, G. Retscher, C. Toth, A. Hasnur-Rabiain, V. Gikas, D. Grejner-Brzezinska, C. Danezis, and T. Moore. Collaborative Navigation as a Solution for PNT Applications in GNSS Challenged Environments – Report on Field Trials of a Joint FIG / IAG Working Group. Journal of applied geodesy, 9(4):244–263, 2016. doi:10.1515/jag-2015-0014
  [BibTeX] [Abstract] [Download PDF]
  

  PNT stands for Positioning, Navigation, and Timing. Space-based PNT refers to the capabilities enabled by GNSS, and enhanced by Ground and Space-based Augmentation Systems (GBAS and SBAS), which provide position, velocity, and timing information to an unlimited number of users around the world, allowing every user to operate in the same reference system and timing standard. Such information has become increasingly critical to the security, safety, prosperity, and overall qualityof-life of many citizens. As a result, space-based PNT is now widely recognized as an essential element of the global information infrastructure. This paper discusses the importance of the availability and continuity of PNT information, whose application, scope and significance have exploded in the past 10–15 years. A paradigm shift in the navigation solution has been observed in recent years. It has been manifested by an evolution from traditional single sensor-based solutions, to multiple sensor-based solutions and ultimately to collaborative navigation and layered sensing, using non-traditional sensors and techniques – so called signals of opportunity. A joint working group under the auspices of the International Federation of Surveyors (FIG) and the International Association of Geodesy (IAG), entitled ‘Ubiquitous Positioning Systems’ investigated the use of Collaborative Positioning (CP) through several field trials over the past four years. In this paper, the concept of CP is discussed in detail and selected results of these experiments are presented. It is demonstrated here, that CP is a viable solution if a ‘network’ or ‘neighbourhood’ of users is to be positioned / navigated together, as it increases the accuracy, integrity, availability, and continuity of the PNT information for all users.

  @article{kealy_collaborative_2016,
  title = {Collaborative {Navigation} as a {Solution} for {PNT} {Applications} in {GNSS} {Challenged} {Environments} – {Report} on {Field} {Trials} of a {Joint} {FIG} / {IAG} {Working} {Group}},
  volume = {9},
  issn = {1862-9024},
  url = {https://www.degruyter.com/view/j/jag.2015.9.issue-4/jag-2015-0014/jag-2015-0014.xml},
  doi = {10.1515/jag-2015-0014},
  abstract = {PNT stands for Positioning, Navigation, and Timing. Space-based PNT refers to the capabilities enabled by GNSS, and enhanced by Ground and Space-based Augmentation Systems (GBAS and SBAS), which provide position, velocity, and timing information to an unlimited number of users around the world, allowing every user to operate in the same reference system and timing standard. Such information has become increasingly critical to the security, safety, prosperity, and overall qualityof-life of many citizens. As a result, space-based PNT is now widely recognized as an essential element of the global information infrastructure. This paper discusses the importance of the availability and continuity of PNT information, whose application, scope and significance have exploded in the past 10–15 years. A paradigm shift in the navigation solution has been observed in recent years. It has been manifested by an evolution from traditional single sensor-based solutions, to multiple sensor-based solutions and ultimately to collaborative navigation and layered sensing, using non-traditional sensors and techniques – so called signals of opportunity. A joint working group under the auspices of the International Federation of Surveyors (FIG) and the International Association of Geodesy (IAG), entitled ‘Ubiquitous Positioning Systems’ investigated the use of Collaborative Positioning (CP) through several field trials over the past four years. In this paper, the concept of CP is discussed in detail and selected results of these experiments are presented. It is demonstrated here, that CP is a viable solution if a ‘network’ or ‘neighbourhood’ of users is to be positioned / navigated together, as it increases the accuracy, integrity, availability, and continuity of the PNT information for all users.},
  number = {4},
  urldate = {2016-07-13},
  journal = {Journal of Applied Geodesy},
  author = {Kealy, A. and Retscher, G. and Toth, C. and Hasnur-Rabiain, A. and Gikas, V. and Grejner-Brzezinska, D. and Danezis, C. and Moore, T.},
  year = {2016},
  pages = {244--263},
  verba = {2.2.3}
  }

• K. Themistocleous, A. Agapiou, B. Cuca, C. Danezis, F. Cigna, C. Margottini, and D. Spizzichino. Methodology for Locale-scale Monitoring for the PROTHEGO Project: The Choirokoitia Case Study. In Earth resources and environmental remote sensing/gis applications vii, volume 10005, page 8. International Society for Optics and Photonics (SPIE),, 2016. doi:10.1117/12.2242047
  [BibTeX] [Abstract] [Download PDF]
  

  PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) is a collaborative research project funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH) – Heritage Plus in 2015–2018 (www.prothego.eu). PROTHEGO aims to make an innovative contribution towards the analysis of geohazards in areas of cultural heritage, and uses novel space technology based on radar interferometry (InSAR) to retrieve information on ground stability and motion in the 400+ UNESCO’s World Heritage List monuments and sites of Europe. InSAR can be used to measure micro-movements to identify geo-hazards. In order to verify the InSAR image data, field and close range measurements are necessary. This paper presents the methodology for local-scale monitoring of the Choirokoitia study site in Cyprus, inscribed in the UNESCO World Heritage List, and part of the demonstration sites of PROTHEGO. Various field and remote sensing methods will be exploited for the local-scale monitoring, static GNSS, total station, leveling, laser scanning and UAV and compared with the Persistent Scatterer Interferometry results. The in-situ measurements will be taken systematically in order to document any changes and geo-hazards that affect standing archaeological remains. In addition, ground truth from in-situ visits will provide feedback related to the classification results of urban expansion and land use change maps. Available archival and current optical satellite images will be used to calibrate and identify the level of risk at the Cyprus case study site. The ground based geotechnical monitoring will be compared and validated with InSAR data to evaluate cultural heritage sites deformation trend and to understand its behaviour over the last two decades.

  @inproceedings{themistocleous_methodology_2016,
  title = {Methodology for {L}ocale-scale {M}onitoring for the {PROTHEGO} {P}roject: {T}he {Choirokoitia} {C}ase {S}tudy},
  volume = {10005},
  shorttitle = {Methodology for locale-scale monitoring for the {PROTHEGO} project},
  url = {http://dx.doi.org/10.1117/12.2242047},
  doi = {10.1117/12.2242047},
  abstract = {PROTHEGO (PROTection of European Cultural HEritage from GeO-hazards) is a collaborative research project funded in the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH) – Heritage Plus in 2015–2018 (www.prothego.eu). PROTHEGO aims to make an innovative contribution towards the analysis of geohazards in areas of cultural heritage, and uses novel space technology based on radar interferometry (InSAR) to retrieve information on ground stability and motion in the 400+ UNESCO's World Heritage List monuments and sites of Europe. InSAR can be used to measure micro-movements to identify geo-hazards. In order to verify the InSAR image data, field and close range measurements are necessary. This paper presents the methodology for local-scale monitoring of the Choirokoitia study site in Cyprus, inscribed in the UNESCO World Heritage List, and part of the demonstration sites of PROTHEGO. Various field and remote sensing methods will be exploited for the local-scale monitoring, static GNSS, total station, leveling, laser scanning and UAV and compared with the Persistent Scatterer Interferometry results. The in-situ measurements will be taken systematically in order to document any changes and geo-hazards that affect standing archaeological remains. In addition, ground truth from in-situ visits will provide feedback related to the classification results of urban expansion and land use change maps. Available archival and current optical satellite images will be used to calibrate and identify the level of risk at the Cyprus case study site. The ground based geotechnical monitoring will be compared and validated with InSAR data to evaluate cultural heritage sites deformation trend and to understand its behaviour over the last two decades.},
  urldate = {2017-06-24},
  author = {Themistocleous, K. and Agapiou, A. and Cuca, B. and Danezis, C. and Cigna, F. and Margottini, C. and Spizzichino, D.},
  year = {2016},
  pages = {8},
  booktitle = {Earth Resources and Environmental Remote Sensing/GIS Applications VII},
  organization = {International Society for Optics and Photonics (SPIE)}
  }

• N. Georgiou, C. Anastasiou, E. A. Tantele, R. A. Votsis, and C. Danezis. Classification of Corrosion Risk Zones using GIS. In Fourth international conference on remote sensing and geoinformation of the environment (rscy2016), volume 9688, page 7. International Society for Optics and Photonics (SPIE),, 2016. doi:10.1117/12.2239553
  [BibTeX] [Abstract] [Download PDF]
  

  Corrosion of steel reinforcement is the major deterioration factor of the RC infrastructures. Several factors are contributing towards increasing the corrosion risk like the exposure and environmental conditions which are a function of the geographical location of the infrastructure. Information for these conditions and their affected areas can be proved valuable at design stage and/or during maintenance planning. This study aims to relate corrosion risk of RC infrastructures with their geographical location. The corrosion risk is quantified through data from NDT methods and subsequently correlated with its location. Therefore high risk areas with structures prone to corrosion deterioration are identified. The latter is implemented via GIS tools in order to create maps that describe how corrosion risk is related to the location of each structure. Two GIS methods are suggested, the grid system and the use of classified areas. Corrosion data has been collected from labs about various constructions in Cyprus and used in conjunction with GIS tools to provide useful information on corrosion identification. The outcome is a digitized map of the Limassol area which indicates the risks levels associated with corrosion of the steel reinforcement.

  @inproceedings{georgiou_classification_2016,
  title = {Classification of {C}orrosion {R}isk {Z}ones using {GIS}},
  volume = {9688},
  url = {http://dx.doi.org/10.1117/12.2239553},
  doi = {10.1117/12.2239553},
  abstract = {Corrosion of steel reinforcement is the major deterioration factor of the RC infrastructures. Several factors are contributing towards increasing the corrosion risk like the exposure and environmental conditions which are a function of the geographical location of the infrastructure. Information for these conditions and their affected areas can be proved valuable at design stage and/or during maintenance planning. This study aims to relate corrosion risk of RC infrastructures with their geographical location. The corrosion risk is quantified through data from NDT methods and subsequently correlated with its location. Therefore high risk areas with structures prone to corrosion deterioration are identified. The latter is implemented via GIS tools in order to create maps that describe how corrosion risk is related to the location of each structure. Two GIS methods are suggested, the grid system and the use of classified areas. Corrosion data has been collected from labs about various constructions in Cyprus and used in conjunction with GIS tools to provide useful information on corrosion identification. The outcome is a digitized map of the Limassol area which indicates the risks levels associated with corrosion of the steel reinforcement.},
  urldate = {2017-06-24},
  author = {Georgiou, N. and Anastasiou, C. and Tantele, E. A. and Votsis, R. A. and Danezis, C.},
  year = {2016},
  pages = {7},
  booktitle = {Fourth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2016)},
  organization = {International Society for Optics and Photonics (SPIE)}
  }

• Y. Vacanas and C. Danezis. The Use of GNSS and Mobile Technologies in the Collection of Productivity Records in Infrastructure Construction Projects. In Forth international conference of remote sensing and Geoinformation of the Environment, RSCy 2016, Paphos, Cyprus, April 2016.
  [BibTeX] [Abstract]
  

  During the construction period of an infrastructure project, records and documentation regarding the conduction and progress of works in a construction project have always been of great significance. Records have an immense importance in the monitoring of the progress of works and improvement of productivity, the preparation of disruption and delay claims and in dispute resolution procedures. Documenting the movement of construction equipment during construction projects is helpful in monitoring and continuously improving construction operations and productivity. The documented trajectories of construction resources (personnel, equipment, and material) allows to analyze travel patterns of construction workers, assess equipment operators’ work, labor activity, or study variability in construction processes. This paper investigates the ability of GNNS-enabled smart devices to collect valuable information related to works processes and productivity within the framework of infrastructure construction projects.

  @inproceedings{vacanas_the_use_2016,
  address = {Paphos, Cyprus},
  title = {The {Use} of {GNSS} and {Mobile} {Technologies} in the {Collection} of {Productivity} {Records} in {Infrastructure} {Construction} {Projects}},
  booktitle = {Forth International Conference of Remote Sensing and {Geoinformation} of the {Environment}, {RSCy} 2016},
  abstract = {During the construction period of an infrastructure project, records and documentation regarding the conduction and progress of works in a construction project have always been of great significance. Records have an immense importance in the monitoring of the progress of works and improvement of productivity, the preparation of disruption and delay claims and in dispute resolution procedures. Documenting the movement of construction equipment during construction projects is helpful in monitoring and continuously improving construction operations and productivity. The documented trajectories of construction resources (personnel, equipment, and material) allows to analyze travel patterns of construction workers, assess equipment operators’ work, labor activity, or study variability in construction processes. This paper investigates the ability of GNNS-enabled smart devices to collect valuable information related to works processes and productivity within the framework of infrastructure construction projects. },
  author = {Vacanas, Y. and Danezis, C.},
  month = {April},
  year = {2016}
  }

2015

• C. Antoniou, V. Gikas, V. Papathanasopoulou, C. Danezis, A. Panagopoulos, I. Markou, D. Efthymiou, G. Yannis, and H. Perakis. Localization and Driving Behavior Classification with Smartphone Sensors in the Direct Absence of Global Navigation Satellite Systems. Transportation Research Record: Journal of the Transportation Research Board, 2489:66–76, January 2015. doi:10.3141/2489-08
  [BibTeX] [Abstract] [Download PDF]
  

  Global navigation satellite systems have tremendous impact and potential in the development of intelligent transportation systems and mobility services and are expected to deliver significant benefits, including increased capacity, improved safety, and decreased pollution. However, there are situations in which there might not be direct location information about vehicles, for example, in tunnels and in indoor facilities such as parking garages and commercial vehicle depots. Various technologies can be used for vehicle localization in these cases, and other sensors that are currently available in most modern smartphones, such as accelerometers and gyroscopes, can be used to obtain information directly about the driving patterns of individual drivers. The objective of this research is to present a framework for vehicle localization and modeling of driving behavior in indoor facilities or, more generally, facilities in which global navigation satellite system information is not available. Localization technologies and needs are surveyed and the adopted methodology is described. The case studies, which use data from multiple types of sensors (including accelerometers and gyroscopes from two smartphone platforms as well as two reference platforms), provide evidence that the opportunistic smart-phone sensors can be useful in identifying obstacles (e.g., speed humps) and maneuvers (e.g., U-turns and sharp turns). These data, when cross-referenced with a digital map of the facility, can be useful in positioning the vehicles in indoor environments. At a more macroscopic level, a methodology is presented and applied to determine the optimal number of clusters for the drivers’ behavior with a mix of suitable indexes.

  @article{antoniou_localization_2015-1,
  title = {Localization and {Driving} {Behavior} {Classification} with {Smartphone} {Sensors} in the {Direct} {Absence} of {Global} {Navigation} {Satellite} {Systems}},
  volume = {2489},
  issn = {0361-1981},
  url = {http://trrjournalonline.trb.org/doi/10.3141/2489-08},
  doi = {10.3141/2489-08},
  abstract = {Global navigation satellite systems have tremendous impact and potential in the development of intelligent transportation systems and mobility services and are expected to deliver significant benefits, including increased capacity, improved safety, and decreased pollution. However, there are situations in which there might not be direct location information about vehicles, for example, in tunnels and in indoor facilities such as parking garages and commercial vehicle depots. Various technologies can be used for vehicle localization in these cases, and other sensors that are currently available in most modern smartphones, such as accelerometers and gyroscopes, can be used to obtain information directly about the driving patterns of individual drivers. The objective of this research is to present a framework for vehicle localization and modeling of driving behavior in indoor facilities or, more generally, facilities in which global navigation satellite system information is not available. Localization technologies and needs are surveyed and the adopted methodology is described. The case studies, which use data from multiple types of sensors (including accelerometers and gyroscopes from two smartphone platforms as well as two reference platforms), provide evidence that the opportunistic smart-phone sensors can be useful in identifying obstacles (e.g., speed humps) and maneuvers (e.g., U-turns and sharp turns). These data, when cross-referenced with a digital map of the facility, can be useful in positioning the vehicles in indoor environments. At a more macroscopic level, a methodology is presented and applied to determine the optimal number of clusters for the drivers’ behavior with a mix of suitable indexes.},
  language = {en},
  urldate = {2016-07-13},
  journal = {Transportation {Research} {Record}: {Journal} of the {Transportation} {Research} {Board}},
  author = {Antoniou, C. and Gikas, V. and Papathanasopoulou, V. and Danezis, C. and Panagopoulos, A. and Markou, I. and Efthymiou, D. and Yannis, G. and Perakis, H.},
  month = {January},
  year = {2015},
  pages = {66--76},
  verba = {2.2.2}
  }

• V. Gikas, C. Antoniou, C. Danezis, T. Mpimis, H. Perakis, V. Papathanasopoulou, and I. Markou. Evaluating Smartphone Navigation Sensors Performance for Driving Event and Maneuver Reconstruction. In Proceedings of the 26th International Union of Geodesy and Geophysics (IUGG) General Assembly 2015, Prague, Czech Republic, June 2015. Iugg.
  [BibTeX] [Abstract] [Download PDF]
  

  In recent years, the continuously increasing capabilities and the decrescent selling prices of contemporary smartphones and mobile devices have made them ideal candidates for the collection of vehicle navigation data for various purposes. Their use is particularly prominent in the scene of Intelligent Transportation System (ITS) applications, the development of road inventory tools as well as for advanced research in transportation studies. However, depending on the scope of their use, the quality requirements (accuracy, availability, continuity, etc.) of a computed navigation solution can vary dramatically ranging from very loose (tens of meters) for comfort to more stringent (meter) standards for monitoring and safety-critical applications. This article attempts a performance characterization of two contemporary smartphones (iPhone 5s, HTC One S) for ITS applications that call for high positioning accuracies, such as driver assistance systems. Specifically, it evaluates their ability to reconstruct a number of specific driving (e.g. braking, accelerating) and maneuvering (e.g. turns, U-turns, zigzags) events collected using a running vehicle at varying speeds. Test data include GNSS positions, tri-axial accelerations and gyroscope measurements. Data processing involves the computation of a reference trajectory using a tactical-grade integrated GNSS/INS system. Data analysis is based on cross-comparisons of the vehicle navigation solution (position, velocity and attitude) and its error estimates obtained using the smartphones against the reference trajectory. Research supported by the Action: ARISTEIA-II (Action’s Beneficiary: General Secretariat for Research and Technology), co-financed by the European Union (European Social Fund – ESF) and Greek national funds.

  @inproceedings{gikas_evaluating_2015,
  address = {Prague, Czech Republic},
  title = {Evaluating {S}martphone {N}avigation {S}ensors {P}erformance for {D}riving {E}vent and {M}aneuver {R}econstruction},
  url = {https://www.czech-in.org/cm/IUGG/CM.NET.WebUI/CM.NET.WEBUI.scpr/SCPRfunctiondetail.aspx?confID=05000000-0000-0000-0000-000000000053&sesID=05000000-0000-0000-0000-000000003118&absID=07000000-0000-0000-0000-000000025271},
  abstract = {In recent years, the continuously increasing capabilities and the decrescent selling prices of contemporary smartphones and mobile devices have made them ideal candidates for the collection of vehicle navigation data for various purposes. Their use is particularly prominent in the scene of Intelligent Transportation System (ITS) applications, the development of road inventory tools as well as for advanced research in transportation studies. However, depending on the scope of their use, the quality requirements (accuracy, availability, continuity, etc.) of a computed navigation solution can vary dramatically ranging from very loose (tens of meters) for comfort to more stringent (meter) standards for monitoring and safety-critical applications. This article attempts a performance characterization of two contemporary smartphones (iPhone 5s, HTC One S) for ITS applications that call for high positioning accuracies, such as driver assistance systems. Specifically, it evaluates their ability to reconstruct a number of specific driving (e.g. braking, accelerating) and maneuvering (e.g. turns, U-turns, zigzags) events collected using a running vehicle at varying speeds. Test data include GNSS positions, tri-axial accelerations and gyroscope measurements. Data processing involves the computation of a reference trajectory using a tactical-grade integrated GNSS/INS system. Data analysis is based on cross-comparisons of the vehicle navigation solution (position, velocity and attitude) and its error estimates obtained using the smartphones against the reference trajectory. Research supported by the Action: ARISTEIA-II (Action’s Beneficiary: General Secretariat for Research and Technology), co-financed by the European Union (European Social Fund – ESF) and Greek national funds.},
  urldate = {2017-06-24},
  booktitle = {Proceedings of the 26th {International} {Union} of {Geodesy} and {Geophysics} ({IUGG}) {General} {Assembly} 2015},
  publisher = {IUGG},
  author = {Gikas, V. and Antoniou, C. and Danezis, C. and Mpimis, T. and Perakis, H. and Papathanasopoulou, V. and Markou, I.},
  month = {June},
  year = {2015}
  }

• V. Gikas, C. Antoniou, T. Mpimis, H. Perakis, and C. Danezis. Performance Evaluation of Vehicle Location Estimation in Heavily Obscured Environments Based on Contemporary Smartphones. In Proceedings of the 6th international conference on indoor positioning and indoor navigation (ipin), Banff, Alberta, Canada, April 2015.
  [BibTeX] [Abstract] [Download PDF]
  

  This paper investigates the tolerance (i.e. accuracy, limitations and potential) of modern smartphones for vehicle location estimation in narrow / deep urban canyons and in partly indoor environments, wherein the role of GNSS becomes truly ancillary compared to other information sources, such as inertial measurement units (IMU). The processing methodology involves the development of a set of algorithms and software routines used to record and manipulate raw navigation measurements of two smartphones (HTC One S, iPHONE 5S) and to compute position trueness and precision statistics in the along- and off-track directions against a rigorously defined reference trajectory. Analysis of vehicle location statistics reveals a deterioration in the standard deviation of trueness and precision mean of the order of 77% and 32% respectively in the deeply obscured environment compared to the open sky scenarios, whereas the along-track statistics exhibit marginally higher mean and standard deviation compared to the off-track values.

  @inproceedings{gikas_performance_2015,
  address = {Banff, Alberta, Canada},
  title = {Performance {Evaluation} of {Vehicle} {Location} {Estimation} in {Heavily} {Obscured} {Environments} {Based} on {Contemporary} {Smartphones}},
  url = {http://ucalgary.ca/ipin2015/files/ipin2015/1570179629.pdf},
  abstract = {This paper investigates the tolerance (i.e. accuracy, limitations and potential) of modern smartphones for vehicle location estimation in narrow / deep urban canyons and in partly indoor environments, wherein the role of GNSS becomes truly ancillary compared to other information sources, such as inertial measurement units (IMU). The processing methodology involves the development of a set of algorithms and software routines used to record and manipulate raw navigation measurements of two smartphones (HTC One S, iPHONE 5S) and to compute position trueness and precision statistics in the along- and off-track directions against a rigorously defined reference trajectory. Analysis of vehicle location statistics reveals a deterioration in the standard deviation of trueness and precision mean of the order of 77% and 32% respectively in the deeply obscured environment compared to the open sky scenarios, whereas the along-track statistics exhibit marginally higher mean and standard deviation compared to the off-track values.},
  urldate = {2016-07-13},
  author = {Gikas, V. and Antoniou, C. and Mpimis, T. and Perakis, H. and Danezis, C.},
  month = {April},
  year = {2015},
  booktitle = {Proceedings of the 6th International Conference on Indoor Positioning and Indoor Navigation (IPIN)}
  }

• C. Antoniou, V. Gikas, V. Papathanasopoulou, C. Danezis, A. Panagopoulos, I. Markou, D. Efthymiou, G. Yannis, and H. Perakis. Localization And Driving Behavior Classification Using Smartphone Sensors In The Direct Absence of Global Navigation Satellite Systems. In Proceedings of the 94th TRB Annual Meeting, Washington DC, USA, January 2015.
  [BibTeX] [Abstract] [Download PDF]
  

  Global navigation satellite systems have tremendous impact and potential in the development of intelligent transportation systems and mobility services and are expected to deliver significant benefits, including increased capacity, improved safety, and decreased pollution. However, there are situations in which there might not be direct location information about vehicles, for example, in tunnels and in indoor facilities such as parking garages and commercial vehicle depots. Various technologies can be used for vehicle localization in these cases, and other sensors that are currently available in most modern smartphones, such as accelerometers and gyroscopes, can be used to obtain information directly about the driving patterns of individual drivers. The objective of this research is to present a framework for vehicle localization and modeling of driving behavior in indoor facilities or, more generally, facilities in which global navigation satellite system information is not available. Localization technologies and needs are surveyed and the adopted methodology is described. The case studies, which use data from multiple types of sensors (including accelerometers and gyroscopes from two smartphone platforms as well as two reference platforms), provide evidence that the opportunistic smart-phone sensors can be useful in identifying obstacles (e.g., speed humps) and maneuvers (e.g., U-turns and sharp turns). These data, when cross-referenced with a digital map of the facility, can be useful in positioning the vehicles in indoor environments. At a more macroscopic level, a methodology is presented and applied to determine the optimal number of clusters for the drivers’ behavior with a mix of suitable indexes.

  @inproceedings{antoniou_localization_2015,
  address = {Washington DC, USA},
  title = {Localization {And} {Driving} {Behavior} {Classification} {Using} {Smartphone} {Sensors} {In} {The} {Direct} {Absence} of {Global} {Navigation} {Satellite} {Systems}},
  url = {http://amonline.trb.org/trb57535-2015-1.1793793/t024-1.1811852/467-1.1812680/15-4885-1.1812684/15-4885-1.1941106?qr=1},
  abstract = {Global navigation satellite systems have tremendous impact and potential in the development of intelligent transportation systems and mobility services and are expected to deliver significant benefits, including increased capacity, improved safety, and decreased pollution. However, there are situations in which there might not be direct location information about vehicles, for example, in tunnels and in indoor facilities such as parking garages and commercial vehicle depots. Various technologies can be used for vehicle localization in these cases, and other sensors that are currently available in most modern smartphones, such as accelerometers and gyroscopes, can be used to obtain information directly about the driving patterns of individual drivers. The objective of this research is to present a framework for vehicle localization and modeling of driving behavior in indoor facilities or, more generally, facilities in which global navigation satellite system information is not available. Localization technologies and needs are surveyed and the adopted methodology is described. The case studies, which use data from multiple types of sensors (including accelerometers and gyroscopes from two smartphone platforms as well as two reference platforms), provide evidence that the opportunistic smart-phone sensors can be useful in identifying obstacles (e.g., speed humps) and maneuvers (e.g., U-turns and sharp turns). These data, when cross-referenced with a digital map of the facility, can be useful in positioning the vehicles in indoor environments. At a more macroscopic level, a methodology is presented and applied to determine the optimal number of clusters for the drivers’ behavior with a mix of suitable indexes.},
  booktitle = {Proceedings of the 94th {TRB} {Annual} {Meeting}},
  author = {Antoniou, C. and Gikas, V. and Papathanasopoulou, V. and Danezis, C. and Panagopoulos, A. and Markou, I. and Efthymiou, D. and Yannis, G. and Perakis, H.},
  month = {January},
  year = {2015}
  }

2014

• C. Antoniou, V. Papathanasopoulou, V. Gikas, C. Danezis, and H. Perakis. Classification of Driving Characteristics using Smartphone Sensor Data. In 3rd Symposium of the European Association for Research in Transport (hEART 2014), Leeds, UK, September 2014.
  [BibTeX] [Abstract] [Download PDF]
  

  Human factors and driving characteristics have become a key consideration and design factor for all kinds of transportation systems and infrastructure elements. Classification of driving behaviors allows a finer perception of real traffic, as it helps distinguish and interpret the way that drivers react to different traffic states and situations. Until recently, obtaining detailed traffic information on individual vehicles required expensive and hard-to-operate, specialized equipment that had to be installed on the vehicle of study (thus making it clear to the driver that s/he was under observation and thus potentially affecting his driving behavior). During the past several years, a new type of phones has been prevalent, so called smartphones. These devices incorporate several powerful sensors that collect much of the same information, as those specialized devices. Of course, the accuracy and performance of these devices are not necessarily in par with their more elaborate and expensive counterparts. However, preliminary results suggest that for practical driving behavior analysis, commodity smartphone sensors might be a plausible option (a comparison and discussion of limitations is available in Antoniou et al., under review).

  @inproceedings{antoniou_classification_2014,
  address = {Leeds, UK},
  title = {Classification of {Driving} {Characteristics} using {Smartphone} {Sensor} {Data}},
  url = {http://transp-or.epfl.ch/heart/2014/Paper%20%20287_Antoniouetal_hEART2014.pdf},
  abstract = {Human factors and driving characteristics have become a key consideration and design factor for all kinds of transportation systems and infrastructure elements. Classification of driving behaviors allows a finer perception of real traffic, as it helps distinguish and interpret the way that drivers react to different traffic states and situations. Until recently, obtaining detailed traffic information on individual vehicles required expensive and hard-to-operate, specialized equipment that had to be installed on the vehicle of study (thus making it clear to the driver that s/he was under observation and thus potentially affecting his driving behavior). During the past several years, a new type of phones has been prevalent, so called smartphones. These devices incorporate several powerful sensors that collect much of the same information, as those specialized devices. Of course, the accuracy and performance of these devices are not necessarily in par with their more elaborate and expensive counterparts. However, preliminary results suggest that for practical driving behavior analysis, commodity smartphone sensors might be a plausible option (a comparison and discussion of limitations is available in Antoniou et al., under review).},
  urldate = {2017-09-24},
  author = {Antoniou, C. and Papathanasopoulou, V. and Gikas, V. and Danezis, C. and Perakis, H.},
  booktitle = {3rd {Symposium} of the {European} {Association} for {Research} in {Transport} ({hEART} 2014)},
  month = {September},
  year = {2014},
  file = {Paper 287_Antoniouetal_hEART2014.pdf:/Users/chrisdanezis/Zotero/storage/4NX87GW9/Paper 287_Antoniouetal_hEART2014.pdf:application/pdf}
  }

2013

• C. Danezis and V. Gikas. An Iterative LiDAR DEM-aided Algorithm for GNSS Positioning in Obstructed/ Rapidly Undulating Environments. Advances in Space Research, 52(5):865–878, September 2013. doi:10.1016/j.asr.2013.05.027
  [BibTeX] [Abstract] [Download PDF]
  

  This paper describes a new algorithm to aid stand-alone GNSS positioning in areas of bad signal reception using a Digital Elevation Model (DEM). Traditional Height-Aiding (HA) algorithms assume either a preset (fixed) value for the receiver elevation or rely on the elevation value that corresponds to the nearest available position fix. This may lead in erroneous receiver elevation estimates that, under circumstances, are inefficient to aid effectively GNSS positioning. In this study, the receiver elevation is updated at every iteration step of the navigation solution through dynamic interpolation of the elevation model. The algorithm, because of its ability to extract and fully exploit the elevation information derived from a digital model, it can prove particularly useful in forested areas with steep-sloped terrain. Extended test runs were undertaken to validate the correctness of the mathematical model and the feasibility of the algorithm and associated software. Particularly, analysis of a dataset acquired in a forested, rapidly undulating environment reveals significant average improvement in all performance metrics of positioning, namely the GNSS position availability (50\%), accuracy (56\%) and external reliability (86\%) compared to the Standard Point Positioning (SPP) solution. Moreover, it was found that the method can cope successfully in marginal operating conditions with situations of bad satellite geometry and satellite signals affected by interference due to tree canopy.

  @article{danezis_iterative_2013,
  title = {An {I}terative {LiDAR} {DEM}-aided {A}lgorithm for {GNSS} {P}ositioning in {O}bstructed/ {R}apidly {U}ndulating {E}nvironments},
  volume = {52},
  issn = {0273-1177},
  url = {http://www.sciencedirect.com/science/article/pii/S0273117713003347},
  doi = {10.1016/j.asr.2013.05.027},
  abstract = {This paper describes a new algorithm to aid stand-alone GNSS positioning in areas of bad signal reception using a Digital Elevation Model (DEM). Traditional Height-Aiding (HA) algorithms assume either a preset (fixed) value for the receiver elevation or rely on the elevation value that corresponds to the nearest available position fix. This may lead in erroneous receiver elevation estimates that, under circumstances, are inefficient to aid effectively GNSS positioning. In this study, the receiver elevation is updated at every iteration step of the navigation solution through dynamic interpolation of the elevation model. The algorithm, because of its ability to extract and fully exploit the elevation information derived from a digital model, it can prove particularly useful in forested areas with steep-sloped terrain. Extended test runs were undertaken to validate the correctness of the mathematical model and the feasibility of the algorithm and associated software. Particularly, analysis of a dataset acquired in a forested, rapidly undulating environment reveals significant average improvement in all performance metrics of positioning, namely the GNSS position availability (50\%), accuracy (56\%) and external reliability (86\%) compared to the Standard Point Positioning (SPP) solution. Moreover, it was found that the method can cope successfully in marginal operating conditions with situations of bad satellite geometry and satellite signals affected by interference due to tree canopy.},
  number = {5},
  urldate = {2015-02-18},
  journal = {Advances in {Space} {Research}},
  author = {Danezis, C. and Gikas, V.},
  month = {September},
  year = {2013},
  publisher = {Elsevier},
  keywords = {Elevation model, GNSS augmentations, Height-aiding, LiDAR, Terrain-aiding},
  pages = {865--878},
  verba = {2.2.1}
  }

• A. Hasnur-Rabiain, A. Kealy, N. Alam, A. Dempster, C. Toth, D. Brzezinska, V. Gikas, C. Danezis, and G. Retscher. Cooperative Positioning using GPS, Low-cost INS and Dedicated Short Range Communications. In Proceedings of the ION 2013 Pacific PNT Meeting, page 769–779, Honolulu, Hawai, USA, April 2013. Institute of navigation (ion).
  [BibTeX] [Abstract] [Download PDF]
  

  Cooperative Positioning (CP) techniques in vehicular ad hoc networks rely primarily on measurements from the Global Positioning System (GPS) to deliver measurements or positions that describe the location of individual vehicles. In urban environments, the reduced quality or complete unavailability of GPS measurements challenge the effectiveness of any CP algorithm. In this paper we propose the fusion of measurements from low cost inertial sensors as a means of improving the CP algorithm when GPS is unavailable. This paper presents results obtained from a practical experiment coordinated under the International Association of Geodesy (IAG) – Commission 4 and the International Federation of Surveyors (FIG) Commission 5, in which ranging information derived from Dedicated Short Range Communications (DSRC) hardware is combined with low-cost GPS and INS measurements communicated between vehicles. The experimental configuration sensors used and data analysis are detailed in this paper as well as preliminary results obtained from the CP algorithm implementation. These results indicate strong promise for the proposed fusion approach showing significant improvements over standalone GPS/INS integration technique.

  @inproceedings{hasnur-rabiain_cooperative_2013,
  address = {Honolulu, Hawai, USA},
  title = {Cooperative {Positioning} using {GPS}, {Low}-cost {INS} and {Dedicated} {Short} {Range} {Communications}},
  url = {http://www.ion.org/publications/abstract.cfm?jp=p&articleID=11039},
  abstract = {Cooperative Positioning (CP) techniques in vehicular ad hoc networks rely primarily on measurements from the Global Positioning System (GPS) to deliver measurements or positions that describe the location of individual vehicles. In urban environments, the reduced quality or complete unavailability of GPS measurements challenge the effectiveness of any CP algorithm. In this paper we propose the fusion of measurements from low cost inertial sensors as a means of improving the CP algorithm when GPS is unavailable. This paper presents results obtained from a practical experiment coordinated under the International Association of Geodesy (IAG) – Commission 4 and the International Federation of Surveyors (FIG) Commission 5, in which ranging information derived from Dedicated Short Range Communications (DSRC) hardware is combined with low-cost GPS and INS measurements communicated between vehicles. The experimental configuration sensors used and data analysis are detailed in this paper as well as preliminary results obtained from the CP algorithm implementation. These results indicate strong promise for the proposed fusion approach showing significant improvements over standalone GPS/INS integration technique.},
  booktitle = {Proceedings of the {ION} 2013 {Pacific} {PNT} {Meeting}},
  publisher = {Institute of Navigation (ION)},
  author = {Hasnur-Rabiain, A. and Kealy, A. and Alam, N. and Dempster, A. and Toth, C. and Brzezinska, D. and Gikas, V. and Danezis, C. and Retscher, G.},
  month = {April},
  year = {2013},
  pages = {769--779}
  }

• A. Kealy, G. Retscher, A. Hasnur-Rabiain, N. Alam, C. Toth, D. A. Grejner-Brzezinska, T. Moore, C. Hill, V. Gikas, C. Hide, C. Danezis, L. Bonenberg, and G. W. Roberts. Collaborative Navigation Field Trials with Different Sensor Platforms. In Proceedings of the 10th Workshop on Positioning Navigation and Communication (WPNC), page 1–6, Dresden, Germany, 2013. doi:10.1109/WPNC.2013.6533262
  [BibTeX] [Abstract]
  

  Collaborative (or cooperative) positioning or navigation uses multiple location sensors with different accuracy on different platforms for sharing of their absolute and relative localizations. Typical application scenarios are dismounted soldiers, swarms of UAV’s, team of robots, emergency crews and first responders. This paper studies the challenges to realize a public and low-cost solution, based on mass users of multiple-sensor platforms. For the investigation field experiments revolved around the concept of collaborative navigation in a week at the University of Nottingham in May 2012. Different sensor platforms have been fitted with similar type of sensors, such as geodetic and low-cost high-sensitivity GNSS receivers, tactical grade IMU’s, MEMS-based IMU’s, miscellaneous sensors, including magnetometers, barometric pressure and step sensors, as well as image sensors, such as digital cameras and Flash LiDAR, and ultra-wide band (UWB) receivers. The employed platforms in the tests include a train on a building roof, mobile mapping vans and personal navigators. The presented preliminary results of the field experiments show that a positioning accuracy on the few meter level can be achieved for the navigation of the different platforms.

  @inproceedings{kealy_collaborative_2013,
  title = {Collaborative {N}avigation {F}ield {T}rials with {D}ifferent {S}ensor {P}latforms},
  doi = {10.1109/WPNC.2013.6533262},
  abstract = {Collaborative (or cooperative) positioning or navigation uses multiple location sensors with different accuracy on different platforms for sharing of their absolute and relative localizations. Typical application scenarios are dismounted soldiers, swarms of UAV's, team of robots, emergency crews and first responders. This paper studies the challenges to realize a public and low-cost solution, based on mass users of multiple-sensor platforms. For the investigation field experiments revolved around the concept of collaborative navigation in a week at the University of Nottingham in May 2012. Different sensor platforms have been fitted with similar type of sensors, such as geodetic and low-cost high-sensitivity GNSS receivers, tactical grade IMU's, MEMS-based IMU's, miscellaneous sensors, including magnetometers, barometric pressure and step sensors, as well as image sensors, such as digital cameras and Flash LiDAR, and ultra-wide band (UWB) receivers. The employed platforms in the tests include a train on a building roof, mobile mapping vans and personal navigators. The presented preliminary results of the field experiments show that a positioning accuracy on the few meter level can be achieved for the navigation of the different platforms.},
  booktitle = {Proceedings of the 10th {Workshop} on {Positioning} {Navigation} and {Communication} ({WPNC})},
  author = {Kealy, A. and Retscher, G. and Hasnur-Rabiain, A. and Alam, N. and Toth, C. and Grejner-Brzezinska, D.A. and Moore, T. and Hill, C. and Gikas, V. and Hide, C. and Danezis, C. and Bonenberg, L. and Roberts, G.W.},
  year = {2013},
  keywords = {collaborative navigation, GNSS, INS, ubiquitous positioning},
  pages = {1--6},
  address = {Dresden, Germany}
  }

2012

• A. Kealy, G. Retscher, N. Alam, A. Hasnur-Rabiain, C. Toth, D. A. Grejner-Brzezinska, T. Moore, C. Hill, V. Gikas, C. Hide, C. Danezis, L. Bonenberg, and G. W. Roberts. Collaborative Navigation with Ground Vehicles and Personal Navigators. In Proceedings of the 2012 International Conference on Indoor Positioning and Indoor Navigation (IPIN), page 1–8, 2012. doi:10.1109/IPIN.2012.6418893
  [BibTeX] [Abstract] [Download PDF]
  

  An integrated positioning solution termed `collaborative positioning’ employs multiple location sensors with different accuracy on different platforms for sharing of their absolute and relative localizations. Typical application scenarios are dismounted soldiers, swarms of UAV’s, team of robots, emergency crews and first responders. The stakeholders of the solution (i.e., mobile sensors, users, fixed stations and external databases) are involved in an iterative algorithm to estimate or improve the accuracy of each node’s position based on statistical models. This paper studies the challenges to realize a public and low-cost solution, based on mass users of multiple-sensor platforms. For the investigation field experiments revolved around the concept of collaborative navigation, and partially indoor navigation. For this purpose different sensor platforms have been fitted with similar type of sensors, such as geodetic and low-cost high-sensitivity GNSS receivers, tactical grade IMU’s, MEMS-based IMU’s, miscellaneous sensors, including magnetometers, barometric pressure and step sensors, as well as image sensors, such as digital cameras and Flash LiDAR, and ultra-wide band (UWB) receivers. The employed platforms in the tests include a train on a building roof, mobile mapping vans, a personal navigator and a foot tracker unit. In terms of the tests, the data from the different platforms are recorded simultaneously. Several field experiments conducted in a week at the University of Nottingham are described and investigated in the paper. The personal navigator and a foot tracker unit moved on the building roof, then trough the building down to where it logged data simultaneously with the vans, all of them moving together and relative to each other. The platforms then logged data simultaneously covering various accelerations, dynamics, etc. over longer trajectories. Promising preliminary results of the field experiments showed that a positioning accuracy on the few m- ter level can be achieved for the navigation of the different platforms.

  @inproceedings{kealy_collaborative_2012,
  title = {Collaborative {N}avigation with {G}round {V}ehicles and {P}ersonal {N}avigators},
  isbn = {978-1-4673-1955-3},
  url = {http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=6418893},
  doi = {10.1109/IPIN.2012.6418893},
  abstract = {An integrated positioning solution termed `collaborative positioning' employs multiple location sensors with different accuracy on different platforms for sharing of their absolute and relative localizations. Typical application scenarios are dismounted soldiers, swarms of UAV's, team of robots, emergency crews and first responders. The stakeholders of the solution (i.e., mobile sensors, users, fixed stations and external databases) are involved in an iterative algorithm to estimate or improve the accuracy of each node's position based on statistical models. This paper studies the challenges to realize a public and low-cost solution, based on mass users of multiple-sensor platforms. For the investigation field experiments revolved around the concept of collaborative navigation, and partially indoor navigation. For this purpose different sensor platforms have been fitted with similar type of sensors, such as geodetic and low-cost high-sensitivity GNSS receivers, tactical grade IMU's, MEMS-based IMU's, miscellaneous sensors, including magnetometers, barometric pressure and step sensors, as well as image sensors, such as digital cameras and Flash LiDAR, and ultra-wide band (UWB) receivers. The employed platforms in the tests include a train on a building roof, mobile mapping vans, a personal navigator and a foot tracker unit. In terms of the tests, the data from the different platforms are recorded simultaneously. Several field experiments conducted in a week at the University of Nottingham are described and investigated in the paper. The personal navigator and a foot tracker unit moved on the building roof, then trough the building down to where it logged data simultaneously with the vans, all of them moving together and relative to each other. The platforms then logged data simultaneously covering various accelerations, dynamics, etc. over longer trajectories. Promising preliminary results of the field experiments showed that a positioning accuracy on the few m- ter level can be achieved for the navigation of the different platforms.},
  booktitle = {Proceedings of the 2012 {International} {Conference} on {Indoor} {Positioning} and {Indoor} {Navigation} ({IPIN})},
  author = {Kealy, A. and Retscher, G. and Alam, N. and Hasnur-Rabiain, A. and Toth, C. and Grejner-Brzezinska, D.A. and Moore, T. and Hill, C. and Gikas, V. and Hide, C. and Danezis, C. and Bonenberg, L. and Roberts, G.W.},
  year = {2012},
  keywords = {absolute localization sharing, atmospheric pressure, barometric pressure sensor, building roof, collaborative navigation, collaborative positioning, digital camera, dismounted soldier, flash LiDAR, Foot, foot tracker unit, geodetic sensor, Geospatial analysis, Global positioning system, GNSS, GNSS receiver, ground vehicle, image sensor, image sensors, indoor radio, INS, integrated positioning solution, iterative algorithm, location sensor, magnetometer, magnetometers, MEMS-based IMU, MEMS-based sensors, mobile mapping vans, multiple-sensor platform, partial indoor navigation, personal navigator, position estimation, Position measurement, radio receivers, relative localization sharing, robot, satellite navigation, seamless indoor/outdoor positioning, Software, statistical model, step sensor, tactical grade IMU, train, UAV, ubiquitous positioning, ultra wideband communication, ultra-wide band receiver, Universal Serial Bus, UWB, UWB receiver},
  pages = {1--8}
  }

• C. Danezis and V. Gikas. Performance Evaluation of a Novel Terrain Aiding Algorithm for GNSS Tracking in Forested Environments. In Proceedings of the 25th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS 2012), page 2083–2090, Nashville, TN, United States, September 2012. Institute of navigation (ion).
  [BibTeX] [Abstract] [Download PDF]
  

  This research investigates the ability of Digital Surface Models (DSM) to aid GNSS tracking in forested environments. Particularly, a new augmentation methodology named “Terrain–Aiding” (TA) is proposed, evaluated and testified. Although “Terrain–Aiding” is a term already used in airborne military navigation, in this paper it is defined with an entirely different meaning; it forms an extension to the well–known technique of Height–Aiding (HA). In order to validate the proposed algorithm and associated software a set of dedicated experiments were carried out in a forested area located nearby Athens, Greece. To accommodate data collection, a specifically designed on–purpose build backpack platform was designed to carry two receivers of different (mapping– and geodetic–) grade characteristics. High accuracy DSM tiles were used to represent the terrain surface. Consequently, the TA algorithm was assessed in terms of GNSS positional availability, accuracy and external reliability in absolute terms (i.e. against a well–defined benchmark trajectory). The results obtained indicate an improvement in GNSS availability of the order of 37\%, when only three satellites are available, whereas GNSS accuracy is significantly improved in cases of marginal conditions. Furthermore, the external reliability was considerably improved by more than 80\%.

  @inproceedings{danezis_performance_2012,
  address = {Nashville, TN, United States},
  title = {Performance {Evaluation} of a {Novel} {Terrain} {Aiding} {Algorithm} for {GNSS} {Tracking} in {Forested} {Environments}},
  url = {http://www.ion.org/publications/abstract.cfm?articleID=10403},
  abstract = {This research investigates the ability of Digital Surface Models (DSM) to aid GNSS tracking in forested environments. Particularly, a new augmentation methodology named “Terrain–Aiding” (TA) is proposed, evaluated and testified. Although “Terrain–Aiding” is a term already used in airborne military navigation, in this paper it is defined with an entirely different meaning; it forms an extension to the well–known technique of Height–Aiding (HA). In order to validate the proposed algorithm and associated software a set of dedicated experiments were carried out in a forested area located nearby Athens, Greece. To accommodate data collection, a specifically designed on–purpose build backpack platform was designed to carry two receivers of different (mapping– and geodetic–) grade characteristics. High accuracy DSM tiles were used to represent the terrain surface. Consequently, the TA algorithm was assessed in terms of GNSS positional availability, accuracy and external reliability in absolute terms (i.e. against a well–defined benchmark trajectory). The results obtained indicate an improvement in GNSS availability of the order of 37\%, when only three satellites are available, whereas GNSS accuracy is significantly improved in cases of marginal conditions. Furthermore, the external reliability was considerably improved by more than 80\%.},
  booktitle = {Proceedings of the 25th {International} {Technical} {Meeting} of the {Satellite} {Division} of the {Institute} of {Navigation} ({ION} {GNSS} 2012)},
  publisher = {Institute of Navigation (ION)},
  author = {Danezis, C. and Gikas, V.},
  month = {September},
  year = {2012},
  pages = {2083--2090}
  }

2011

• C. Danezis. Positioning Techniques in Difficult GNSS Environments. In 6th Annual Meeting of the Hellenic Association of Rural & Surveying Engineers, Ioannina, Greece, July 2011. Hellenic association of rural & surveying engineers.
  [BibTeX] [Download PDF]

  @inproceedings{danezis_dodoni_2011,
  address = {Ioannina, Greece},
  type = {Invited {Speaker}},
  title = {Positioning {Techniques} in {Difficult} {GNSS} {Environments}},
  author = {Danezis, C.},
  url = {https://polytexnikanea.blogspot.com/2011/07/blog-post_07.html},
  month = {July},
  year = {2011},
  publisher = {Hellenic Association of Rural \& Surveying Engineers},
  booktitle = {6th {Annual} {Meeting} of the {Hellenic} {Association} of {Rural} \& {Surveying} {Engineers}}
  }

• C. Danezis. Assessment of the ability of digital terrain models to aid GPS tracking of people and animals. PhD thesis, University {College} {London}, September 2011.
  [BibTeX] [Abstract] [Download PDF]
  

  The advent of global navigation satellite systems, and especially GPS, signified a new era in navigation. Although GPS tends to be a panacea in terms of positioning and tracking, there are still cases whereby severe problems can render navigation virtually impossible. Difficult GNSS environments such as forests, heavy canopy covered areas, or urban canyons can have a negative impact on the propagation of satellite signal and introduce large errors in positioning due to signal attenuation. Several techniques have been developed to deal with this issue, e.g. integrated GNSS/INS navigation configurations. This thesis focuses on the application of terrain aiding and its impact on the availability, accuracy, and reliability of GNSS positioning. Furthermore, it examines the impact of using GNSS receivers of different grade and different chipset sensitivity in such operations. Two main experiments were carried out; the first was conducted in the mountains of Transylvania, in Romania. This project was sponsored by the European GNSS supervisory authority, and involved the tracking of animals (bears in this case). The second experiment was held in Greenwich Park, London, using an accurate terrain model, kindly provided by the Ordnance Survey of Great Britain. In both cases, new algorithms have been developed to combine satellite tracking with local terrain models to improve positioning performance. The results indicate that in the case of standard sensitivity receivers the use of an accurate digital terrain model can improve positioning availability by as much as 74\%, and the accuracy of normal four-satellite positioning by a factor of up to five. Furthermore, it was found that, for both standard and high sensitivity receivers, the external reliability of position fixes can be improved by an average of 40\%, and up to 90\% in some cases.

  @phdthesis{danezis_assessment_2011,
  title = {Assessment of the ability of digital terrain models to aid {GPS} tracking of people and animals},
  url = {http://discovery.ucl.ac.uk/1331877/},
  abstract = {The advent of global navigation satellite systems, and especially GPS, signified a new era in navigation. Although GPS tends to be a panacea in terms of positioning and tracking, there are still cases whereby severe problems can render navigation virtually impossible. Difficult GNSS environments such as forests, heavy canopy covered areas, or urban canyons can have a negative impact on the propagation of satellite signal and introduce large errors in positioning due to signal attenuation. Several techniques have been developed to deal with this issue, e.g. integrated GNSS/INS navigation configurations. This thesis focuses on the application of terrain aiding and its impact on the availability, accuracy, and reliability of GNSS positioning. Furthermore, it examines the impact of using GNSS receivers of different grade and different chipset sensitivity in such operations. Two main experiments were carried out; the first was conducted in the mountains of Transylvania, in Romania. This project was sponsored by the European GNSS supervisory authority, and involved the tracking of animals (bears in this case). The second experiment was held in Greenwich Park, London, using an accurate terrain model, kindly provided by the Ordnance Survey of Great Britain. In both cases, new algorithms have been developed to combine satellite tracking with local terrain models to improve positioning performance. The results indicate that in the case of standard sensitivity receivers the use of an accurate digital terrain model can improve positioning availability by as much as 74\%, and the accuracy of normal four-satellite positioning by a factor of up to five. Furthermore, it was found that, for both standard and high sensitivity receivers, the external reliability of position fixes can be improved by an average of 40\%, and up to 90\% in some cases.},
  language = {eng},
  urldate = {2013-07-12},
  school = {University {College} {London}},
  publisher = {University {College} {London}},
  author = {Danezis, C.},
  month = {September},
  year = {2011}
  }

2007

• C. Danezis and P. A. Cross. Bear Ethology Around Romania (BEAR). In European GNSS Supervisory Authority: Growing Galileo ’07, Brussels, Belgium, November 2007. European gnss supervisory authority.
  [BibTeX] [Abstract] [Download PDF]
  

  Environmental factors which cause difficulty with, for example, GPS and/or Galileo signal reception include tree canopies and urban canyons. This project developed strategies to mitigate some of these environmental factors. Such problems arise naturally from the study of animal behaviour. The experimental ‘vehicles’ for this project were bears in the Transylvanian Alps. The project methodology was based on the comparison of different techniques for animal tracking – high sensitivity (multiple-correlators) and post-processing of pseudo-range signals. In practice, four bears were equipped with multi-mode receivers so that tracking signals could be compared. In addition, innovative algorithms were developed and evaluated for ‘height-aiding’. In parallel, the bears were tracked by foresters and monitored visually. The major innovation related to post-processing techniques for the individual pseudo-range signals. There is a problem with signal availability in environments where there is extensive tree cover. The purpose of the BEAR project was to develop improved tracking techniques for use in difficult GNSS environments. A secondary set of activities that was related to wildlife management used data derived from the core aspects of the project.

  @inproceedings{danezis_brussels_2007,
  address = {Brussels, Belgium},
  title = {{Bear} {Ethology} {Around} {Romania} ({BEAR})},
  author = {Danezis, C. and Cross, P.A.},
  abstract = {Environmental factors which cause difficulty with, for example, GPS and/or Galileo signal reception include tree canopies and urban canyons. This project developed strategies to mitigate some of these environmental factors. Such problems arise naturally from the study of animal behaviour. The experimental 'vehicles' for this project were bears in the Transylvanian Alps. The project methodology was based on the comparison of different techniques for animal tracking – high sensitivity (multiple-correlators) and post-processing of pseudo-range signals. In practice, four bears were equipped with multi-mode receivers so that tracking signals could be compared. In addition, innovative algorithms were developed and evaluated for 'height-aiding'. In parallel, the bears were tracked by foresters and monitored visually. The major innovation related to post-processing techniques for the individual pseudo-range signals. There is a problem with signal availability in environments where there is extensive tree cover. The purpose of the BEAR project was to develop improved tracking techniques for use in difficult GNSS environments. A secondary set of activities that was related to wildlife management used data derived from the core aspects of the project.},
  booktitle = {European {GNSS} {Supervisory} {Authority}: {Growing} {Galileo} '07},
  publisher = {European GNSS Supervisory Authority},
  month = {November},
  url = {https://www.gsa.europa.eu/communication/events-highlights/growing-galileo-07},
  year = {2007},
  }