星载合成孔径雷达变脉冲重复频率技术研究

A Study on Pulse Repetition Frequency Variation Technology of Spaceborn Synthetic Aperture Radar

高分辨率星载合成孔径雷达系统在大斜视情形下存在距离徙动严重的问题,导致雷达回波录取窗可能跨脉冲重复间隔。为了解决大斜视高分辨率宽幅成像的波位设计和无效原始数据问题,根据距离徙动曲线,提出星载滑动聚束工作模式下连续变脉冲重复频率与变采样开启波门方法,确保成像时间内所有的回波信号被完整接收。通过斜视情形波位设计和性能仿真结果以及机载飞行试验获得的大斜视情形下的变脉冲重复频率高质量图像,验证了所提方法的有效性。

The high resolution spaceborne synthetic aperture radar system has large range cell migration in large squint case,the radar echo window may cross pulse repetition interval.To solve the questions of beam position design and useless data in wide swath imaging of large squint and high resolution,the method of pulse repetition Frequency variation and sampling wave gate variation according to range cell migration is proposed in this paper,thus the echoes are completely received within the reception window.The effectiveness of this method is testified by the results from the beam position design and simulation results in squint case and high resolution images from flight test of large squint case and pulse repetition frequency variation.