Improving the quality of information received from synthetic aperture radars implementing innovative passive reflectors

In the last two decades the use of satellite remote sensing (RS) methods and technologies to study the ongoing processes on land surface and more specifically to obtain information about movements of the earth's surface due to geodynamic processes with different magnitudes (earthquakes, tectonic movements, landslides and collapse processes and etc.) has become ubiquitous due to more data available from operational synthetic aperture radars. The main driving force for this increase of the application of RS in studying the mentioned processes are the technological progress in the space industry, the creation of RS instruments for monitoring different objects from the Earth's surface with better spatial accuracy, improvement of the computational capabilities of modern computer systems as well as the increasingly and widespread development of innovative SAR data processing methods. One of the data sources for the thematic categories under the Copernicus program is the Sentinel-1 (S-1) satellite, which provides reliable SAR data regardless of atmospheric conditions. After their thematic processing by using the method of differential interferometry (DInSAR) and its improvements it is possible to obtain information about undelaying topography as well as the displacements that have occurred on the earth's surface. In order to increase the quality of this information for non-urbanized territories, it is necessary to deploy artificial, passive persistent reflectors (also known as corner reflectors - CRs) at well-known positions having verified backscattering characteristics. And since on the territory of Bulgaria, to the best knowledge of the authors, there are no available such passive reflectors as described above that are used to improve the reliability of the information obtained in SAR data processing from S-1 we designed, developed, and put into operation on a pilot basis a network of six reflectors. In this paper we present the setting-up process as well as first results after their deployment at selected site to study surface deformations caused by active fault structures.