基于双向重采样的高分辨率前视成像算法  

High-resolution forward-looking imaging based on bi-directional resampling

作　　者：郑志瀛 谭鸽伟[1] 蒋丁一 ZHENG Zhiying;TAN Gewei;JIANG Dingyi(College of information Science and Engineering,Huaqiao University,Xiamen 361021,China)

机构地区：[1]华侨大学信息科学与工程学院,厦门361021

出　　处：《航空学报》2024年第4期228-241,共14页Acta Aeronautica et Astronautica Sinica

基　　金：华侨大学研究生科研创新基金(17014082025);华侨大学人才项目(10BS312)。

摘　　要：高速平台双基SAR的高速机动特性和双基前视构型使其高分辨率成像面临严峻挑战。在该体制下,发射机以侧视方式发送信号,而高速运动的接收平台在前视模式下接收回波。由于高速度、大加速度的存在,使SAR回波的距离徙动现象以及二维耦合、空变特性都更加严重,传统的“停走停”模型不再适用。为了解决上述问题,提出了适用于高速平台的“非停走停”斜距方程及回波模型,然后通过分析信号中的空变分量及其对回波相位的影响,提出了基于双向重采样的成像算法。该算法有效补偿了SAR回波在距离和方位向的空变相位误差,提高了高速平台双基SAR的前视聚焦性能,通过仿真验证了所提算法的有效性。The high maneuvering characteristics and bistatic forward-looking configuration of the high maneuvering bi⁃static forward-looking SAR makes it a serious challenge for high-resolution imaging.In this system,the transmitter transmits signals in the side-looking mode,while the high maneuvering receiver platform receives echoes in the forward-looking mode.Due to the existence of high speed and acceleration,the range cell migration and the 2-D cou⁃pling and spatial variation characteristics of SAR echoes are more severe,so the traditional“stop-and-go”model is no longer applicable.To solve the above problem,a“non-stop-and-go”slant range equation and an echo model for the high maneuvering platform are firstly put forward.Then,a high-resolution imaging algorithm based on bi-directional resampling is proposed by analyzing the spatial variation components in the signal and their effects on the echo phase.The proposed algorithm effectively compensates for the 2-D spatial variation and improves the forward-looking focusing performance of bistatic SAR on high maneuvering platforms.Simulation results confirm the effectiveness of the pro⁃posed algorithm.

关 键 词：高速平台双基SAR 前视成像 “非停走停”回波模型 二维空变特性 双向重采样算法 

分 类 号：V243.2[航空宇航科学与技术—飞行器设计]