Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China.
National Key Laboratory of Sciences and Technology on Microwave Imaging, Beijing 100190, China.
Sensors (Basel). 2018 Aug 10;18(8):2620. doi: 10.3390/s18082620.
The Chinese first fully polarimetric space-borne synthetic aperture radar (SAR)-Gaofen-3 (GF-3) was launched in August 2016, which operates at the C-band and the resolution can reach 1 m. Polarimetric SAR calibration is a procedure that corrects the polarization distortion of a measured scattering matrix by referring to the scattering matrix of a known target. The present paper describes the principle, design, manufacture, and measurement results of a novel polarimetric active radar calibrator (PARC) designed for GF-3. A new design method for PARC was presented and two dual-polarized antennas with very high polarization purity were used. The internal calibration technique was introduced to ensure balance in the amplitude and phase, which ensures the precision of the PARC's scattering matrices. The results we obtained through measurement in the microwave anechoic chamber and experiments in in-orbit calibration agree well with the theoretical predictions, and the novel PARC presented is proved to be well suited for polarization and radiometric calibration of GF-3.
中国首颗全极化合成孔径雷达（SAR）卫星——高分三号（GF-3）于 2016 年 8 月发射，工作在 C 波段，分辨率可达 1 米。极化合成孔径雷达定标是一种通过参考已知目标的散射矩阵来校正测量散射矩阵的极化失真的过程。本文介绍了一种新型极化有源雷达定标器（PARC）的原理、设计、制造和测量结果，该定标器专为 GF-3 设计。提出了一种新的 PARC 设计方法，并使用了两个具有非常高极化纯度的双极化天线。介绍了内部校准技术，以确保幅度和相位的平衡，从而确保 PARC 散射矩阵的精度。在微波消声室测量和在轨校准实验中获得的结果与理论预测吻合较好，证明所提出的新型 PARC 非常适合 GF-3 的极化和辐射校准。
