分析了用于对地成像的天基合成孔径激光雷达(SAL)系统指标,采用10 m口径膜基衍射光学系统以满足功率口径积的要求,用合成孔径雷达相控阵天线模型分析了器件参数和衍射光学系统的波束方向图。针对大口径衍射光学系统存在的孔径渡越问题,提出了基于数字信号处理的高距离分辨率信号补偿聚焦方法。研究结果表明:10 m衍射口径天基SAL系统有可能对远距离特定目标进行高数据率、高分辨率成像跟踪,该技术的实现具有一定的可行性。

The system indexes of a space-based synthetic aperture LiDAR (SAL) system used for ground imaging are analyzed. A membrane-based diffractive optical system with a 10 m aperture is chosen to satisfy the requirement of power aperture product. Based on the synthetic aperture radar phased array antenna model, the device parameters and beam patterns in the diffractive optical system are analyzed. Aiming at the aperture transition problem existing in the diffractive optical system with a large aperture, a signal compensation and focusing method with a high range resolution is proposed based on digital signal processing. The research results show that based on this space-based SAL with a 10 m diffractive aperture, the image tracking with a high resolution and a high data rate to the specific long-distance targets is possible. Moreover, the realization of this technique can be feasible.