波数域近场ISAR成像及形变校正  

Near-field ISAR Imaging and Deformation Correction in Wavenumber Domain

作　　者：卢光宇 万明慧 陈潇翔 吴宁宁 白杨 LU Guangyu;WAN Minghui;CHEN Xiaoxiang;WU Ningning;BAI Yang(National Key Laboratory of Radar Signal Processing,Xidian University,Xi’an 710071,Shaanxi,China;Shanghai Radio Equipment Research Institute,Shanghai 201109,China)

机构地区：[1]西安电子科技大学雷达信号处理全国重点实验室,陕西西安710071 [2]上海无线电设备研究所,上海201109

出　　处：《制导与引信》2025年第1期32-41,共10页Guidance & Fuze

基　　金：上海航天科技创新基金(SAST2022-064)。

摘　　要：与传统近场逆合成孔径雷达(inverse synthetic aperture radar,ISAR)成像算法相比,基于传统Omega-K近场成像算法的ISAR成像不会产生几何形变。但是由于雷达平台所需载频高、成像积累时间有限,这使得采用传统Omega-K近场成像算法直接在空间域进行聚焦时会出现图像混叠,且需要进行大量补零操作,无法实现快速高效成像。针对上述问题提出了一种波数域近场ISAR成像及形变校正算法。通过分析斜视成像二维波数域支撑区的斜拉特性,结合坐标旋转和方位谱重采样的方法,实现了波数谱的正侧化,再将子孔径数据聚焦在方位波数域,实现了方位向聚焦,最后通过Chirp-Z变换进行形变校正。经仿真验证,所提算法在解决形变校正问题的同时还能大幅减少运算量,显著提升了成像效率。Inverse synthetic aperture radar(ISAR)imaging does not produce geometric deformation based on the traditional Omega-K near-field imaging algorithm compared with the traditional near-field ISAR imaging algorithm.However,due to the high carrier frequency required by the radar platform and the limited imaging accumulation time,the imaging aliasing occurs when the traditional Omega-K near-field imaging algorithm is used to focus directly in the spatial domain,and a large number of zero-padding operations is required,which makes it impossible to achieve fast and efficient imaging.Aiming at the above problems,a near-field ISAR imaging and deformation correction algorithm in wavenumber domain was proposed.By analyzing the cable-stayed characteristics of the two-dimensional wavenumber domain support area of squint imaging,combined with coordinate rotation and azimuth spectrum resampling,the positive lateralization of the wavenumber spectrum was realized.The sub-aperture data was focused in the azimuth wavenumber domain,and the azimuth focusing was realized.Finally,the deformation correction was performed by Chirp-Z transform.The simulation results show that the proposed algorithm can greatly reduce the computational complexity and improve the imaging efficiency while solving the deformation correction problem.

关 键 词：近场成像 逆合成孔径雷达 波数域 形变校正 Omega-K算法 

分 类 号：TN957.52[电子电信—信号与信息处理]