Polarimetric Calibration of Mini SAR based on UAV Platform

Abstract

The Miniaturized Synthetic Aperture Radar has the characteristics of ‘anytime imaging’, day or night from an airborne platform, so it is a promising candidate for many applications, such as high-resolution terrain elevation mapping, coherent change detection, and crevasse detection. To reduce the phase difference, channel crosstalk, channel imbalance, and other effects between the channels (single, dual, or fully polarimetric), the author adopts a new polarimetric calibration method. This method uses the reflector corner as the reference calibration point to accurately calibrate the vertical channel system gain and the imbalance factor of the four polarimetric channels, without the need to make assumptions about the scattering characteristics of the scene. This method is suitable for Ku-band multi-rotor UAVs Miniaturized SAR data. Compared with the Quegan algorithm, it can obtain more accurate amplitude estimation and channel imbalance estimation.