主星带辅星的分布式SAR二次干涉动目标检测方法

A Method of Dual-Interferometry Moving Targets Indication Based on Spaceborne Parasitic Distributed SAR

设计了一种以满足GMTI功能为主同时兼顾InSAR功能,由1颗主星和4颗辅星组成的双椭圆绕飞被动稳定编队构型,利用绕飞编队的对称星消除垂直轨迹基线从而获得虚拟的单纯沿航迹基线。提出了对称星二次干涉处理方法,将杂波对消与沿航迹干涉(ATI)技术结合起来,在杂波对消后进行动目标检测,并指导在检测到动目标存在的区域进行二次干涉,降低了虚警率,提高了检测精度;同时利用长基线获得较小的最小可检测速度,二次干涉提供的参差基线解速度模糊提高了最大不模糊速度,从而增大了速度可检测范围。计算机仿真结果表明该方法即使在地面场景高程有较大起伏时也能有效进行动目标检测并进行精确测速和定位。

In order to realize the function of Ground Moving Target Indication （GMTI） and Interferometric SAR （InSAR）, this paper designs a passively stabilized double ellipse satellite formation which is composed of one main satellite and four samll satellites. It can obtain a virtual pure along-track baseline by using the symmetrical small satellites in the ellipse orbit to suppress the cross-track baseline. This paper proposes a new signal processing method for GMTI named dual-interferometry which combines the clutter suppression and Along-Track Interferometry （ATI）. It performs the GMTI after the clutter suppression, directs the dual-interferometry in the moving targets existing area, decreases the false alarm ratio and increases the precision of location and velocity measurement. The system can obtain the minor minimum detectable velocity by utilizing the long baseline, and increase the maximum detectable unambiguous velocity by utilizing the stagger baseline derived from the double ellipse satellite formation, so as to expand the detectable range of velocity. The simulation shows that the method can perform GMTI, location and velocity measurement effectively even if the terrain is rather uneven.