Numerical and experimental evaluation of polarimetric calibration using hybird corner reflectors

摘要

In this paper, we evaluate the polarimetric calibration method that relies only on the characteristics of the calibration targets and requires no assumptions regarding scene statistics and radar characteristics. It allows the correction of polarimetric distortions of the radar system using only three types of calibration target: trihedral, dihedral, the 22.5° and 45°-rotated dihedral corner reflectors. The method is simple, accurate and yet robust in terms of field deployment in some cases. Evaluation and testing of the algorithm was made at microwave anechoic chamber measurements, numerical simulation, and airborne L-band Pi-SAR data. It is found that the amplitude error can be achieved to as small as 0.5dB, while the phase error is within 5° in high resolution of Pi-SAR system. Due to the sensitivity of 22.5°-rotated dihedral to rotation angle, it is not recommended to use the 22.5° -rotated dihedral for polarimetric calibration.