Geodetic synthetic aperture radar in Finland

Abstract

Synthetic Aperture Radar (SAR) is a powerful remote sensing technology that provides detailed images of larger areas, regardless of weather conditions or daylight. This study delves into the efficacy and performance of passive corner reflectors deployed in Finland, with a specific focus on their suitability for Synthetic Aperture Radar (SAR) calibration. The corner reflectors, strategically positioned across diverse sites, offer a cost-effective and low-maintenance alternative to active transponders. However, their large size and weight, particularly in longer wavelengths, present challenges in deployment, and their autonomous settling effect may introduce distortions in deformation measurements. This research rigorously examined the precision and reliability of these reflectors, addressing their response to varying weather conditions and potential geometric alterations over extended deployment periods. Two reflectors, situated in Metsähovi and Loviisa, both characterized by a triangular trihedral design were chosen for comparative analysis. The study was conducted from September 2022 to June 2023 and is investigated the influence of snow depth and temperature on signal to clutter ratio values. It also examined how corner reflectors behave under various weather conditions. This research can provide insights into the utilization of corner reflectors for SAR calibration, guiding future applications in geodetic measurements and large-scale processes.