Simulation research on the whole process of spaceborne XTI-SAR oceanic eddy detection

Abstract

Oceanic eddy is a highly occurring marine phenomenon in the ocean, characterized by closed circulation. Oceanic eddy can cause changes in Sea Surface Height (SSH) and will make the SSH around the center of the oceanic eddy to be higher or lower than the surrounding area, so the identification of oceanic eddy can be achieved by detecting the change of SSH. Traditionally, radar altimeter is an important means to measure the sea surface height, but its resolution is low, so it can’t effectively detect sub-mesoscale oceanic eddies. With its all-time, all-weather, wide-swath and high-resolution characteristics, Synthetic Aperture Radar (SAR) has become a research hotspot in oceanic eddy remote sensing detection. It uses radar antennas from different angles of view to form a baseline, called interferometric SAR, which can achieve the measurement of SSH. In this paper, a signal level simulation model of oceanic eddy for spaceborne cross-track interferometric SAR(XTI-SAR) is established, and an evaluation method based on ideal interferometric factors is introduced. In the experiments, we analyze the influence on the error of oceanic eddy SSH measurement at different sea states. The results show that the increase of wind speed will increase the height measurement error of oceanic eddy, and the difference of wind direction will cause obvious changes in the height measurement error.