关键词: 水电站, 合成孔径雷达, 角反射器, SAR定位, 雷达反射截面积, Sentinel-1

Abstract: Corner reflectors(CR)serve as a crucial tool for high-precision interferometric synthetic aperture radar (InSAR) monitoring, with their reflective performance and geolocation accuracy playing a key role in InSAR deformation monitoring and result interpretation. Existing research on CR geolocation accuracy focuses on flat terrain, lacking studies addressing complex topographical settings. This paper presents a comprehensive method for CR geolocation accuracy analysis, combining SAR geolocation and radar cross section (RCS) analysis techniques, and validated using the CR array deployed at a mountainous reservoir head area of a giant hydropower station located within a river canyon. Results indicate that out of the 10 corner reflectors (CRs) in the reservoir head area, 8 exhibits good accuracy, while 2 demonstrates suboptimal precision. The RCS of the 8 high-precision CRs increases by over 5 dBm² after installation, with an average increase of 10.24 dBm², representing an average growth of 66.2%, and the average SAR geolocation errors in the azimuth and range directions are -0.601 and -0.013 m, respectively. The accuracy of the 2 remaining CRs is limited due to the foreshortening effect, with SAR geolocation errors in the azimuth direction of 5.83 and -9.02 m, and range errors of 1.37 and -0.73 m respectively, highlighting that terrain complexity should be taken into consideration when deploying CRs in mountainous canyon regions. The findings of this study provide the first evaluation of the applicability of SAR geolocation in mountain and canyon scenarios and offer crucial insights into the accuracy of the CR array at the giant hydropower station reservoir head area, providing important references for high-precision InSAR deformation monitoring and result interpretation in mountainous canyon regions.

Key words: hydropower station, synthetic aperture radar, corner reflector, SAR geolocation, radar cross section, Sentinel-1