一种自聚焦的弹载SAR成像方法  

PGA-based Autofocus Method for Missile-borne SAR Imaging

作　　者：谭覃燕[1] 宋耀良[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,江苏南京210094

出　　处：《南京理工大学学报》2009年第5期663-667,共5页Journal of Nanjing University of Science and Technology

基　　金：国防预研基金

摘　　要：针对传统聚束式合成孔径雷达(SAR)成像算法对弹载SAR运动误差补偿困难的问题,该文提出采用相位梯度自聚焦算法(PGA)实现导弹成像过程中的相位误差校正。该方法利用方位滑窗对各像素点进行质量评估,从而挑选出质量最好的孤立特显点用于相位误差估计,并通过对相位误差的迭代修正获得其估计值。该文研究的PGA算法是非模型的相位误差估计方法,因此对任意阶相位误差都有非常好的自聚焦性能。理论和成像仿真结果表明,该方法具有运算量小、收敛速度快和估计精度高的特点。Based on the problem that the traditional spotlight synthetic aperture radar （SAR） imaging algorithms have difficulties in compensating the motion error of a missile-borne SAR, this paper proposes to utilize the phase gradient algorithm （PGA） to achieve missile-borne SAR＇s phase error correction. This method evaluates the quality of each pixel in the image by sliding window in the azimuth direction to select the high-quality scatters for the phase error estimation, and then obtains the estimation phase error by iterative phase correction. The PGA algorithm presented here is not phase-errormodel-based, so it has a well-deserved reputation for arbitrary high-order autofocus. The result of theoretical analysis and simulation shows that this method has less operation load, faster convergence speed and high estimation accuracy.

关 键 词：自聚焦算法 弹载合成孔径雷达 雷达成像 

分 类 号：TN958[电子电信—信号与信息处理]