Space-based Deformation Monitoring of Coastal Urban Areas: The Case of Limassol’s Coastal Front

In the last five years, the urban development of Limassol City has rapidly increased in the sectors of industry, trade, real estate, and many others. This exponentially increased urban development introduces several concerns about the aggravation of the land subsidence in the Limassol coastal front. Fifty Copernicus Sentinel-1 data from 2017-2021 have been processed and analyzed using the Sentinel Application Platform (SNAP) and the Stanford Method for Persistent Scatters (StaMPS). A case study for the identification and analysis of the elements (PS) in pixels in a series of interferograms, and then, the quantity of the land displacements in the Line of Sight, in the Limassol coastal front, is presented in this research, with the 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, taking into account that there are a significant number of skyscrapers planned to be built, this study attempts a preliminary assessment of the impact these structures will pose on the coastal front of the area of Limassol

Space-Based Displacement Monitoring of Coastal Urban Areas: The Case of Limassol’s Coastal Front

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 Limasso

Earth Observation in the EMMENA Region: Scoping Review of Current Applications and Knowledge Gaps

Earth observation (EO) techniques have significantly evolved over time, covering a wide range of applications in different domains. The scope of this study is to review the research conducted on EO in the Eastern Mediterranean, Middle East, and North Africa (EMMENA) region and to identify the main knowledge gaps. We searched through the Web of Science database for papers published between 2018 and 2022 for EO studies in the EMMENA. We categorized the papers in the following thematic areas: atmosphere, water, agriculture, land, disaster risk reduction (DRR), cultural heritage, energy, marine safety and security (MSS), and big Earth data (BED); 6647 papers were found with the highest number of publications in the thematic areas of BED (27%) and land (22%). Most of the EMMENA countries are surrounded by sea, yet there was a very small number of studies on MSS (0.9% of total number of papers). This study detected a gap in fundamental research in the BED thematic area. Other future needs identified by this study are the limited availability of very high-resolution and near-real-time remote sensing data, the lack of harmonized methodologies and the need for further development of models, algorithms, early warning systems, and services

Space-Based Displacement Monitoring of Coastal Urban Areas: The Case of Limassol’s Coastal Front

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

Considerations and Multi-Criteria Decision Analysis for the Installation of Collocated Permanent GNSS and SAR Infrastructures for Continuous Space-Based Monitoring of Natural Hazards

Over the past few decades, the global population and the built environment’s vulnerabil-ity 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 re-quired 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

Initial Validation Results from the Integrated Use of Permanent GNSS Stations and SAR Corner Reflectors in Cyprus by means of the CyCLOPS Strategic Research Infrastructure

The Cyprus Continuously Operating Natural Hazards Monitoring and Prevention System, abbreviated CyCLOPS, is a national strategic research infrastructure unit, with main objective the systematic study of geohazards in Cyprus and the broader EMMENA region. The project was coordinated by Cyprus University of Technology in collaboration with the German Aerospace Center (DLR), and holds the support of the critical national stakeholders, such as the Geological Survey Department and the Department of Lands and Surveys. CyCLOPS is comprised of two main components; (a) a multi-parametric network of sensors (MPN) established throughout the government-controlled areas of Cyprus and (b) an Operation Centre (OC). The MPN is comprised by a permanent and a mobile segment, which is deployed at areas of interest. The permanent segment includes six permanent sites, each of which contains a Tier-1 GNSS reference station co-located with two calibration-grade triangular trihedral corner reflectors of 1.5m inner length to account for both the ascending and descending tracks of SAR satellite missions, such as ESA’s Sentinel-1. Furthermore, the GNSS equipment is co-located with precise weather stations and tiltmeters. The mounting considerations for the permanent segment are aligned with the most stringent specifications, as outlined by UNAVCO, IGS and EPN. Therefore, besides its zero-order geodetic nature, the unit aims to become a calibration and validation (Cal/Val) infrastructure for current and future SAR satellites constellations. The mobile segment is comprised by the same grade of GNSS equipment, hosted on a specifically designed mobile configuration, which enables flexibility in the deployment of the stations, even at harsh environments, to monitor dynamic phenomena, such as landslides. Furthermore, the mobile segment includes electronic corner reflectors (ECRs), which are, again, co-located with the GNSS sensors, weather stations and tiltmeters. CyCLOPS achieved full operational capacity in June 2021. Since then, it continuously monitors the geodynamic regime of the southeastern Mediterranean area along with several active landslides occurring at the western part of the island. Consequently, the objective of this research is to deliver a brief presentation of the infrastructure, the first experience after 1.5 years of system operation, and outline results from the analysis of SAR products using our Corner Reflectors. The latter can be carried out, for instance, by means of the SAR Calibration Tool (SCT), developed by Aresys Srl, to estimate accurate geometric and radiometric calibration for Sentinel-1 products over Cyprus. Radiometric calibration will be assessed by means of a Point-Target-Analysis (PTA) on the SLCs to estimate parameters such as peak signal power, clutter power and RCS. The now almost 2 year long dataset will be analysed in full in order to verify the temporal stability of the network and to identify, for instance, drops in accuracy due to collection of precipitation in the CRs. The geometric or geolocation accuracy will be assessed, taking into account the effects of propagation delay of the SAR signal through the troposphere and ionosphere, and geodynamical effects which influence the previously determined, e.g. through surveying, CR position such as the coordinate reference frame and solid earth tides

Impact assessment of the catastrophic earthquakes of 6 February 2023 in Turkey and Syria via the exploitation of satellite datasets

Turkey due to its location within the collision zone between the Eurasian, African and Arabian Plates, is a region prone to earthquakes. The country mostly lies on the Anatolian micro-plate, bounded by two major strike-slip fault zones, i.e., the North and the East Anatolian Fault. On 6 February 2023, the activation of a large segment of the East Anatolian Fault generated two earthquakes of 7.8 and 7.5 magnitude, in southern Turkey. The seismic risk is greater along the plate boundaries, however due to the frequency of earthquake occurrence throughout Turkey, detailed seismic risk maps are crucial and need to be continuously updated towards operational purposes, and as the optimal means towards decision making for disaster risk reduction. Extensive Synthetic Aperture Radar (SAR) satellite image analysis was performed to determine ground displacements caused by the seismic sequence in the wider area around the two epicenters. Pre-seismic line of sight displacements, as well as co-seismic deformation, were estimated, providing critical information about the surface rupture and the overall ground deformation in the affected areas. Earthquakes can induce landslides and other ground displacements causing extensive damage to buildings and infrastructure. Therefore, optical (e.g., Sentinel-2, PlanetScope) and SAR (Sentinel-1) imagery were exploited as a useful tool for assessing the impact of earthquakes on the ground. The monitoring and mapping of these changes, in conjunction with SAR analysis, as well as information on building infrastructure and population density, highlight the overall damage assessment in the region, thus, allowing a better understanding of the impact of earthquakes while providing a more effective response and recovery efforts for decision makers and local authorities towards disaster risk reduction