地球同步轨道SAR凝视成像变脉冲重复频率技术

实现对特定区域凝视观测成像是地球同步轨道SAR（GEO SAR）非常重要的应用。针对地球同步轨道SAR凝视观测回波大距离徙动造成信号接收窗口难以选择的问题，提出了一种地球同步轨道SAR凝视成像变脉冲重复频率（PRF）设计方法。给出了变PRF设计的准则，详细推导了周期性变PRF过程中脉冲丢失的位置，分析对成像质量的影响，采用后向投影算法对方位非均匀采样信号进行成像聚焦。最后仿真验证变PRF设计的有效性。

The Technology of Pulse Repetition Frequency Variation for Geosynchronous Orbit SAR with Staring Imaging

The staring observation of a certain region for geosynchronous orbit synthetic aperture radar (GEO SAR) is very important application. Due to the big SAR echo range migration in staring imaging which makes the signal reception window be difficult to choose, a pulse repetition frequency (PRF) variation method for geosynchronous orbit staring imaging is put forward. Firstly, the design criterion of pulse repetition frequency variation is given, and then both of the location of the missing pulse and the influence on imaging quality owing to pulse repetition frequency (PRF) variation are deduced in detail. The back projection (BP) algorithm is adapted to non-uniform sampling signal imaging focusing. Finally, the simulation is used to verify the effectiveness of the PRF variation. Numerical simulations have demonstrated the effectiveness of the approach proposed.