Detecting and Removing Phase Jitters for the Phase Synchronization of LT-1 Bistatic SAR

作者：Yonghua Cai, Junfeng Li, Yachao Wang, Qingyue Yang, Yanyan Zhang, Yafeng Chen, Pingping Lu, Robert Wang · 发表于：IEEE Geoscience and Remote Sensing Letters · 年份：2023 · DOI：10.1109/lgrs.2023.3318125 · 被引用次数：12 · 研究领域：Synthetic Aperture Radar (SAR) Applications and Techniques、Advanced SAR Imaging Techniques、Underwater Acoustics Research

Phase synchronization plays a crucial role in the LuTan-1 (LT-1) bistatic synthetic aperture radar (BiSAR) system, as it aims to eliminate additional azimuthal phase modulation caused by oscillator differences. However, for the pulse alternating transmission system operating in the L-band, the presence of radio frequency interference (RFI) poses an inevitable challenge. Serious RFIs introduce phase jitters, compromising the accuracy of synchronization. In this letter, an effective method for detecting and removing phase jitters is proposed to enhance synchronization accuracy. In the proposed method, the jitter features are separated by the iteratively reweighted least squares (IRLS) in the instantaneous frequency domain based on the established synchronization phase model. Then the jitter positions are detected by correlated peaks between the designed convolutional kernels and jitters. Finally, a polynomial model is utilized to remove jitters and assist in phase unwrapping. The synchronization phases acquired by the LT-1 mission are used to verify the feasibility of the proposed algorithm. The improved imaging quality demonstrates the effectiveness of the proposed method and confirms its ability to ensure the high-precision generation of the LT-1 BiSAR images.