Ku波段机载极化SAR数据定标

针对极化合成孔径雷达(SAR)数据采集过程中出现的通道串扰、通道不平衡问题,利用Ku波段机载全极化SAR数据进行定标试验研究。进行了极化通道间干涉相位去除,以及包含相位校正、串扰校正和通道不平衡校正的极化SAR定标处理。对三面角反射器后向散射的分析表明:经定标处理后,极化通道不平衡降至1 dB以内,通道串扰降至-17 dB以下,极化特征图与理想三面角更为接近。Freeman-Durden分解结果表明:经定标处理后,极化SAR数据能较为准确地反映地物主要散射机制信息。

Experimental Study on Ku-Band Airborne Full Polarimetric SAR Calibration

An experiment of polarimetric synthetic aperture radar (SAR) calibration is conducted. The data are obtained by using an airborne Ku-band full polarimetric SAR system. A polarimetric calibration procedure including phase calibration, cross-talk calibration and channel imbalance calibration is applied to the data. Quantitative analysis on the backscattering from the trihedral corner reflectors demonstrates that after calibration, the imbalance between co-polarized channels is reduced to be less than 1 dB, while the cross-talk is reduced to be less than -17 dB. After calibration, the polarimetric signatures of these trihedral corner reflectors are closer to the ideal trihedral corner reflector. Freeman-Durden decomposition result of the calibrated data shows that the dominant polarimetric scattering mechanisms are consistent with the land cover, which demonstrates the effectiveness of the polarimetric calibration method.