摘要
机动平台大斜视SAR大场景成像时,加速度和大斜视角的存在使成像参数存在严重的二维空变性,极大限制了常规SAR成像方法的聚焦深度。为此,提出了基于多普勒域块处理的机动平台大斜视SAR成像方法。该方法通过子区域成像与全局数据块拼接,构建了高效的混合聚焦框架。在距离向处理中,对空变的距离徙动进行线性近似,并采用Keystone变换实现大场景的空变距离徙动校正;方位压缩时,进行子区域划分和多普勒域数据块的频域相位滤波处理,通过最小化局部多普勒参数差异实现高效空变补偿。理论分析和仿真结果表明,所提方法具有较高的运算效率,能够有效扩展成像场景的聚焦深度。
During large-scene imaging of highly squinted synthetic aperture radar(SAR)mounted on maneuver-ing platforms,the existence of acceleration and large squint angle makes the imaging parameters have severe two-dimen-sional spatial variability,significantly limiting the focusing depth of conventional SAR imaging methods.To address this,an imaging method for highly squinted SAR mounted on maneuvering platforms based on Doppler-domain block processing is proposed.This method constructs an efficient hybrid focusing framework by employing sub-region imaging and global data block stitching.In the range processing,the spatially variant range cell migration(RCM)is linearly approximated,and the Keystone transform is used to realize the spatially variant RCM correction of the large scene.Dur-ing azimuth compression,sub-region segmentation and frequency-domain phase filtering of Doppler-domain data blocks are performed,minimizing the local Doppler parameter differences to achieve efficient spatially variant compensation.Theoretical analysis and simulation results demonstrate that the proposed method exhibits high computational efficiency and effectively extends the depth of focus for large imaging scenes.
作者
李根
孙翱
王伟
刘雪松
LI Gen;SUN Ao;WANG Wei;LIU Xuesong(Unit 91550 of PLA,Dalian 116023,China;College of Intelligent Systems Science and Engineering,Harbin Engineering University,Harbin 150001,China;Postdoctoral Research Workstation Sub-Station of Unit 92493 of PLA,Dalian 116023,China)
出处
《雷达科学与技术》
北大核心
2025年第4期396-406,共11页
Radar Science and Technology
基金
国家自然科学基金(No.62271163)。
关键词
机动平台
大斜视SAR
多普勒域块处理
频域相位滤波
maneuvering platform
highly squinted SAR
Doppler-domain block processing
frequency-domain phase filtering
作者简介
李根,男,博士,工程师,主要研究方向为制导与控制、雷达信号处理;孙翱,男,博士,正高级工程师,主要研究方向为测控总体设计;王伟,男,博士,教授、博士生导师,主要研究方向为智能导航与探测技术;刘雪松,女,硕士,工程师,主要研究方向为制导与控制。
