一种用于TOPS SAR-GMTI的空时自适应处理方法

发布时间：2018-09-18 21:58

【摘要】：针对在循序渐近对地扫描合成孔径雷达(TOPS SAR)模式下静止背景杂波的多普勒带宽很大,在有限的脉冲重复频率(PRF)条件下,会导致背景杂波出现严重的多普勒模糊问题,提出了一种基于谱压缩的空时自适应处理方法进行杂波抑制.经过谱压缩操作后,杂波的多普勒带宽减小到与其瞬时带宽相同,再利用空时自适应处理(STAP)方法进行杂波抑制,使得杂波抑制性能得到明显改善.同时,由于动目标径向速度的存在,会导致其多普勒频谱产生偏移,而直接采用匹配滤波方法对动目标进行聚焦,会造成虚假目标的出现.为了避免出现这一现象,可利用Deramp处理方法对动目标进行聚焦处理,能有效避免虚假目标的产生.同时利用TOPS SAR模式获得连续的重叠率很高的全孔径TOPS SAR图像,可以实现动目标的轨迹跟踪处理.最后,通过仿真实验验证了所提方法的有效性.
[Abstract]:The Doppler bandwidth of stationary background clutter is very large in the (TOPS SAR) mode of progressive ground scanning synthetic aperture radar (GSAR). Under the condition of limited pulse repetition rate (PRF), the background clutter will appear a serious Doppler ambiguity problem. A space-time adaptive processing method based on spectral compression is proposed for clutter suppression. After spectrum compression operation, the Doppler bandwidth of clutter is reduced to the same as its instantaneous bandwidth, and the clutter suppression is performed by using space-time adaptive processing (STAP) method, which improves the performance of clutter suppression obviously. At the same time, because of the existence of radial velocity of moving target, the Doppler spectrum of moving target will be offset, and the direct use of matched filtering method to focus the moving target will result in the appearance of false target. In order to avoid this phenomenon, the Deramp processing method can be used to focus the moving target, which can effectively avoid the false target. At the same time, TOPS SAR mode is used to obtain continuous TOPS SAR images with high overlap rate, which can be used to track moving targets. Finally, the effectiveness of the proposed method is verified by simulation experiments.
【作者单位】：西安电子科技大学雷达信号处理国家重点实验室;
【基金】：国家自然科学基金优秀青年基金资助项目(61222108) 国家自然科学青年基金资助项目(61301292,61101245)
【分类号】：TN958

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