一种用于低信噪比场景的改进PGA算法  

An Improved Phase Gradient Autofocus Algorithm forLow Signal-to-Noise Ratio Scenes

作　　者：张文虎 向聪[1] 李涛[1] 张晓东[1] ZHANG Wenhu;XIANG Cong;LI Tao;ZHANG Xiaodong(Xi'an Electronic Engineering Research Institute,Xi'an 710100)

机构地区：[1]西安电子工程研究所,西安710100

出　　处：《火控雷达技术》2025年第1期73-78,共6页Fire Control Radar Technology

摘　　要：在合成孔径雷达(Synthetic Aperture Radar,SAR)自聚焦算法中,采用相位梯度自聚焦算法(Phase Gradient Autofocus,PGA)能有效估计相位误差(PE)。低信噪比场景使用该算法估计的相位误差区别大,导致最终成像聚焦效果鲁棒性差,这严重限制了PGA算法在成像中的应用。本文提出了一种针对低信噪比场景的改进PGA方法,采用固定窗长滑窗提高数据信噪比,降低质量差的距离单元入选几率,实现算法稳定性。实测数据处理结果表明所提算法具有较高的估计精度和稳健性。In the synthetic aperture radar(SAR)autofocus algorithm,the phase gradient autofocus(PGA)algorithm can effectively estimate phase errors(PE).The estimated phase error obtained using this algorithm in low signal-to-noise ratio scenarios varied greatly,resulting in poor robustness in the final imaging focus effect,which severely limited the application of the PGA algorithm in imaging.In this article,an improved PGA method was proposed based on low signal-to-noise ratio scenarios,using a fixed window length sliding window to improve data signal-to-noise ratio and reduced the likelihood of poor-quality distance units being selected,achieving algorithm stability.The results of the measured data processing showed that the proposed algorithm has high estimation accuracy and robustness.

关 键 词：合成孔径雷达 低信噪比 相位梯度自聚焦算法 滑窗 

分 类 号：TN95[电子电信—信号与信息处理]