摘要
法拉第效应对星载极化SAR测量和定标有着不可忽略的影响,在极化定标的同时必须考虑法拉第旋转角的校正,而法拉第旋转角Ω和SAR系统通道不平衡f随时间变化的特性给极化定标增加了很大的难度。R.Touzi提出了一种利用分布目标对称性估计Ω和f的方法,本文对R.Touzi方法进行了深入研究,发展了选择对称目标并将其用于失真参数估计的流程,分析了对称性误差对R.Touzi方法估计精度的影响,,给出了使得估计值达到要求精度的目标对称性所需满足的条件;并利用实际星载SAR极化数据对该方法进行了实验研究。
The effort coming from Faraday rotation cannot be ignored on spaceborne Polarimetric SAR measurement and calibration. So Faraday rotation has to be corrected at the time of polarimetric calibration. Yet the variability of Faraday rotation and SAR channel imbalance with time and scene has greatly increased the difficulty of polarimetric calibration. R. Touzi has recently proposed a method that using symmetry property of distributed targets to estimate Faraday rotation and channel imbalance. This paper presents a thorough study of R. Touzi＇s method. A procedure of selecting potential symmetric distributed targets and applying it for the estimation of distortion parameters are first developed here and then this paper analyzes the effect of symmetry error on the estimation precision, which leads to a condition that the targets＇ symmetry property has to satisfy given a required precision of the estimation of these parameters. Finally,some simulation experiment with real PolSAR data is carried out to validate the method.
出处
《电子测量技术》
2008年第2期46-49,53,共5页
Electronic Measurement Technology
