信号处理2025，Vol.41Issue(11)：1750-1762,13.DOI:10.12466/xhcl.2025.11.002
一种大惯导误差条件下前斜视SAR自聚焦算法
A Forward-Squinted Synthetic Aperture Radar Autofocus Algorithm Under Large Trajectory Deviations
摘要
Abstract
This study proposes an improved autofocusing algorithm to address the forward-squinted synthetic aperture ra-dar(SAR)imaging degradation caused by large trajectory deviations.The degradation causes inaccuracies in Doppler ambiguity estimation and generates diverse defocusing patterns,which severely degrade image focus quality.First,a Doppler center estimation method based on range frequency domain sub-band signals is proposed.Baseband Doppler centroids are estimated for sub-band signals via the correlation function,enabling the construction of a binary linear equation system that relates sub-band centroids to Doppler ambiguity numbers determined using least squares(LS)esti-mation.This approach effectively resolves the inaccuracy in Doppler ambiguity estimation.Second,an adaptive windowing-weighted phase gradient autofocus(WPGA)approach based on superpixel segmentation is presented,accu-rately segmenting and extracting defocused target regions by employing pixel dissimilarity.Adaptively adjusting the win-dow length according to the dimensions of the superpixel units within the target regions significantly enhances the accu-racy of phase error estimation.Simulations and real-data SAR processing results demonstrate that the proposed algorithm maintains superior focusing capability and robustness under large trajectory deviations.关键词
大惯导误差/自聚焦算法/多普勒中心估计/自适应加窗Key words
large trajectory deviations/autofocus algorithm/Doppler centroid estimation/adaptive windowing分类
信息技术与安全科学引用本文复制引用
高伟奇,冉磊,刘峥,谢荣..一种大惯导误差条件下前斜视SAR自聚焦算法[J].信号处理,2025,41(11):1750-1762,13.基金项目
雷达信号处理全国重点实验室支持计划项目(JKW202306,KGJ202504) （JKW202306,KGJ202504）
装备预研项目(3020506010204) （3020506010204）
中央高校基本科研业务费(ZYTS25146)National Key Laboratory of Radar Signal Processing(JKW202306,KGJ202504) （ZYTS25146）
Equipment pre-research project(3020506010204) （3020506010204）
Fundamental Research Funds for the Central Universities(ZYTS25146) （ZYTS25146）
