基于多通道合成的优于0.1m分辨率的机载SAR系统

针对合成孔径雷达(SAR)高分辨率成像的应用需求,该文给出一种基于单通道发射、多通道并行接收的新的高分辨率SAR系统实现方案。SAR系统共有8个接收通道,信号带宽达到3.2 GHz,具有高分辨率成像、InSAR干涉成像以及全极化成像功能。文中提出一种新的采用空间辐射测量和频偏误差修正测量的分段测量与综合补偿的通道传递误差测量补偿方法,有效解决了高分辨率SAR宽频带收发系统中关键的多通道接收幅度相位误差校正问题,并在国内首次获得了优于0.1 m分辨率的SAR图像。文中详细介绍了系统的组成方案以及主要技术性能指标,重点探讨和分析了多通道系统的频带合成、系统幅度相位误差测量补偿、运动误差补偿和成像处理等实现技术,给出了测量、补偿和成像的试验结果。通过实际飞行试验,验证了高分辨率SAR系统的技术及方案的有效性和可行性。

An Airborne SAR with 0.1 m Resolution Using Multi-channel Synthetic Bandwidth

In order to meet the growing demands for high resolution SAR imaging, this paper describes a new single channel transmit, multi-channel parallel receive high resolution SAR system. The system operates with 8 parallel receive channels to obtain a wide bandwidth up to 3.2 GHz, and also features high resolution, InSAR and PolSAR imaging capability. A novel method of transfer error measurement and compensation is presented in the paper. This method based on radiation calibration and frequency shift correction estimation could implement multi-channel amplitude and phase correction effectively. For the first time in China, a resolution of better than 0.1 m is achieved with the airborne SAR system. This paper introduces the architecture and main specifications of the SAR system, and discusses several important aspects of high resolution imaging in detail, including the bandwidth synthesis, transfer error correction, motion compensation and image formation. Flight experiments demonstrate the high resolution imaging capability of the SAR system.