基于马尔可夫模型的分布式卫星SAR-ATI空域自适应滤波方法

A Spatially Adaptive Filtering Method for Distributed Satellite SAR-ATI Based on MRF Model

与单颗卫星合成孔径雷达(SAR)系统相比,编队飞行的分布式卫星雷达系统的优势在于,孔径的尺寸和几何不受限制,自主编队控制可形成多个灵活、有效的基线,在单个编队下可多任务交替进行,能够更好地完成高精度三维地形测绘、地面和空中运动目标检测、大测绘带高分辨率成像等任务。其中,在合成孔径雷达-沿航迹干涉(SAR-ATI)工作模式下,由于编队构型、任务需求等诸多因素的影响,ATI得到的相位中不仅包含了运动目标相位,还包含了切航迹基线引起的随地形起伏变化的相位和多种去相干因素引起的随机变化的噪声,造成了大量的虚警。文中提出了一种新的分布式卫星SAR-ATI空域自适应滤波方法,较好地去除了切轨迹干涉相位和随机噪声,提升了混合基线下SAR-ATI的检测性能。文中基于分布式星载SAR仿真系统进行了算法验证和性能评价,实验结果证明了该方法的良好性能。

Compared with monostatic spaceborne synthetic aperture radar(SAR),the advantages of distributed spaceborne SAR fly with formation configuration are that aperture size and geometry may not be limited and can form multiple flexible and effective baselines.Based on single formation,distributed spaceborne SAR can implement multiple tasks better,such as high precision interferometric SAR,ground moving target indication,airborne moving target indication,and wide swath and high resolution imaging.Under the working mode of SAR-along track interferometry(SAR-ATI),due to many factors like the satellites formation configuration and mission requirements,the phase of ATI not only includes the phase of moving target,but also includes the across track phase corresponds to the topography variance and the decorrelation noise,which results in high false alarm.A new spatially adaptive filtering method for distributed satellites SAR-ATI is proposed,which can remove the across track interferometric phase and noise efficiently,and improve the detection performance of SAR-ATI.Based on the distributed spaceborne SAR simulation system,the simulation experiments are carried out to verify the effectiveness of the proposed method.