ABSTRACT

Spaceborne P-band full-polarimetric wideband synthetic aperture radar (SAR) will be affected by ionospheric phase dispersion and polarimetric dispersion. An improved contrast optimization autofocus (COA) method using four polarization channel data is proposed to compensate for both phase dispersion and polarimetric dispersion. The basis and steps of the method are given. Its performance is analysed by typical target simulation under clutter background and compared with traditional COA method for single channel. The residual quadratic phase error (QPE) of single channel compensated by traditional method may exceed 45° focusing threshold, while the proposed method can reduce the error to less than 10°. Due to the lack of spaceborne P-band SAR data, we simulate the effect of ionosphere on P-band SAR based on ALOS2 PALSAR2 data and verify the proposed method. The simulation result shows the proposed method is effective and superior to traditional method.

摘要

星载P波段全极化宽带合成孔径雷达（SAR）会受到电离层相位色散和极化色散的影响。提出了一种改进的使用四偏振通道数据的对比度优化自动聚焦 (COA) 方法来补偿相位色散和偏振色散。给出了该方法的依据和步骤。通过杂波背景下的典型目标仿真分析其性能，并与传统的单通道COA方法进行比较。传统方法补偿的单通道残余二次相位误差（QPE）可能超过45°聚焦阈值，而本文提出的方法可以将误差降低到10°以下。由于缺乏星载P波段SAR数据，我们基于ALOS2 PALSAR2数据模拟了电离层对P波段SAR的影响，并验证了所提出的方法。仿真结果表明，该方法是有效的，优于传统方法。