单发双收SAR系统通用极化定标算法

摘要

单发双收极化SAR系统只接收两个通道数据，使得极化定标可用的先验信息减少；同时由于这类系统收发极化方式的多样性(包括多种收发极化组合的双极化和简缩极化模式)，目前还没有通用的定标算法。对此，该文提出了一种新的通用极化定标算法，可以广泛应用于多种收发极化组合的单发双收SAR系统。该算法利用常见的三面角、0°二面角与45°二面角作为理想点目标，无需对目标场景和系统作假设，可以直接估计系统的发射端和接收端失真项。该文理论推导了定标算法的求解过程，仿真分析了定标器误差对失真参数估计的影响，通过点目标的定标结果和极化特征图验证了该通用定标算法的有效性。%　　The single-transmitting-dual-receiving polarimetric SAR system has only two receving channels, which induces lack of prior information for calibration. Due to the polarization diversity of this kind of system (which operates on different dual and compact polarimetric modes), there has not a general algorithm currently. In this paper, a new general calibration algorithm is proposed for single-transmitting-dual-receiving polarimetric SAR system, which can be widely applied to diverse polarization modes. The transmitting and receiving distortion can be estimated using trihedral, 0° dihedral and 45° dihedral as ideal point targets without any assumption on the scene and system. The basic principle of this new algorithm is induced theoretically. The effect of calibrator error on the distortion estimation is analyzed by simulation. Point targets’ calibration results and polarization signatures verify this algorithm.