Estimation and correction of vibration-induced range cell migration for FMCW synthetic aperture ladar

作     者：Li, Guangzuo Zhang, Zenghui Zhang, Yifei Fang, Sujuan Hong, Wen Wu, Yirong 

作者机构：Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn Shanghai 200240 Peoples R China Chinese Acad Sci Inst Elect Beijing 100190 Peoples R China 

出 版 物：《APPLIED OPTICS》 (Appl. Opt.)

年 卷 期：2020年第59卷第9期

页      面：2874-2882页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：National Natural Science Foundation of China 

主　　题：Aperture synthesis Image quality Phase compensation Remote sensing Synthetic aperture imaging Synthetic aperture radar 

摘      要：Synthetic aperture ladar (SAL) is a newly developed imaging device for remote sensing application. Owing to its short wavelength (3-5 orders of magnitude shorter than radar), SAL is very sensitive to platform vibration. For frequency-modulated continuous-wave SAL (FMCW-SAL), the platform vibration induces an additional range cell migration (RCM) to the SAL image. The vibration-induced RCM (VI-RCM) deteriorates the image quality. The VI-RCM is a unique problem for the FMCW-SAL imaging. To address this problem, a raw-data-driven method is proposed to correct the VI-RCM in this paper. First, the signal model was developed to show the VI-RCM in FMCW-SAL echo. Then, based on the model, the differential phase function (DPF) is constructed for the adjacent range profiles. The DPF is a single-frequency signal with its frequency being proportional to the relative range shift between the adjacent range profiles. Based on the DPF, the relative range shift is estimated. After the estimation of all the relative range shifts, the VI-RCM is calculated and corrected. Experiments are performed. The simulated experiment demonstrated the feasibility, accuracy, and efficiency of the proposed method, and the real data processing result verified the effectiveness of the proposed method for FMCW-SAL in practical applications. (C) 2020 Optical Society of America