一种SAR运动参数估计及成像方法基于DCFT变换

An Improved Method for Motion Compensation in SAR Imaging Based on DCFT

SAR运动参数估计是SAR成像技术研究中的一项关键技术,目前国际上普遍采用的方法是GPS+INS导航系统进行运动参数估计。国内由于技术等方面的原因导航参数的估计精度远远不能满足SAR成像要求,目前只能从回波中提取平台运动参数,其中较为典型的方法是PGA、子孔径相关法等,而DCFT作为一种新的CHIRP信号参数估计方法能快速、精确的估计CHIRP信号的相关参数。本文提出利用DCFT方法估计SAR运动参数,并以此为基础对传统的RD成像算法加以改进,提出了一种基于DCFT变换的改进RD成像算法。

SAR motion parameters estimation is the critical technique in SAR imaging processing. The classical method is to estimate the parameters by GPS/INS. However, for some reasons, the precision of estimation in china is far low to meet the requirement of SAR imaging, and we can only exact the parameters using the SAR echo data, the classical algorithms include PGA, time - frequency analysis. DCFT （ Discrete chirp - Fourier transform） is a new CHIRP signal parameters estimation method, .which can estimate those parameters quickly and accurately. In this paper, a new parameter estimation method is present based on DCFT transform, and a new SAR imaging algorithms is given using stretching technique, which modify the traditional RD algorithms.