Experience in deploying radar corner reflectors for InSAR monitoring

Abstract

This work aims to analyze the effectiveness of corner reflectors deployment designed in various for InSAR monitoring by the Sentinel-1 satellite. Method. The accuracy of determining the spatial movements of the surface by the InSAR method in the places where the corner reflectors are deployed depends on their size, as well as the signal-to-clutter ratio on the radar images. Therefore, it is necessary to assess the backscattering intensity on radar images for the selected territory before installing the corner reflector. In places where corner reflectors are to be deployed, an increase in backscatter should be at least 10 dB. The orientation of the corner reflectors was performed based on Sentinel-1 satellite orbit parameters, which were obtained from the Heavens Above web resource. The analysis of the backscatter intensity time series on radar images was carried out using the online platform EO Browser. Results. The effectiveness of deployment and monitoring of trihedral triangular corner reflectors measuring 0.5 m and 1 m was studied. The research results made it possible to generalize the experience of deploying temporary corner reflectors and use them to design reflector structures for permanent monitoring using radar sensing. The maximum autonomy and constant value of the effective scattering area of the triangular corner reflector is ensured thanks to the equipped protective screen that prevents atmospheric precipitation from entering the reflector. Unlike three-sided corner reflectors, which are oriented to the ascending or descending orbit of the satellite, the circular four-sided corner reflector provides an increase in the intensity of backscatter on radar images taken from different orbits and different satellites. The circular quadrilateral reflector, which was deployed for continuous monitoring, is characterized as a universal reflector for all possible sensors that will conduct radar imaging. Scientific novelty and practical significance are in the confirmation of the effectiveness of the use of ground corner reflectors to increase the intensity of backscattering on radar images. Tested and improved designs of reflectors can be used when creating a network for constant monitoring, which will ensure millimeter accuracy in determining the spatial movements of the earth's surface and engineering structures by the InSAR method.