基于DBF-SCORE的Ka SAR-GMTI信号处理方法研究*

在SAR信号处理中为增大接收增益，提高系统回波的信噪比，可利用数字波束形成(DBF)技术(扫描接收技术)生成灵活控制的高增益窄波用于多通道接收、处理回波信号。分析并推导了距离向多通道的回波信号，然后详细分析了基于偏置相位中心天线（DPCA）的SAR GMTI处理方法。在此基础上给出了一种使用DPCA杂波抑制技术处理基于时变加权DBF SCORE回波的Ka SAR GMTI处理方法，并给出了系统实现原理。与其他SAR GMTI处理方法相比较，使用DBF技术可以提升系统信噪比，有助于改善杂波抑制性能。通过仿真，验证了用DPCA技术处理基于DBF动目标回波的有效性。

Algorithm of Ka SAR GMTI based on DBF SCORE

To increase the receive gain and signal to noise ratio (SNR) in the SAR signal processing, the technique of digital beam forming (DBF) (scan on receive, SCORE) can be employed to receive and process echo signal by forming a high gain and sharp beam pattern to receive the pulse echoes. In this paper, the echo signal of each channel on elevation is analyzed firstly, and the method of SAR GMTI processing is given and analyzed. On this basis of SAR GMTI, this paper presents an algorithm of Ka SAR GMTI using DPCA clutter suppression technique to process echoes based on the time variant weighting DBF SCORE and further presents the block diagram of system realization. Compared with other SAR GMTI processing methods, using DBF technique can enhance the system SNR and improve the performance of suppressing clutter. Finally, moving target simulation results validate that using DPCA to process moving target echoes based on DBF is as same as the common echoes, that is, prove its effectiveness of the proposed method.