Three-Dimensional Trajectory Reconstruction of Moving Target With L-Antenna in Airborne WasSAR-GMTI

Wide-angle staring synthetic aperture radar ground moving target indication (WasSAR-GMTI) has been widely recognized for its long-term observation capabilities of fixed areas and its achievement in moving target tracking. Recently, the research on moving target trajectory reconstruction has also raised interest. However, the neglect of height-dimensional information makes it difficult to apply in the scene with terrain undulation. In this paper, a three-dimensions (3-D) trajectory reconstruction method with L-antenna which combines interferometry SAR (InSAR) and GMTI technique is proposed. Meanwhile, it’s the first time that L-antenna is applied in 3-D geo-location of moving target. Firstly, the echo is segmented into several sub-apertures and the lever arm compensation and back projection (BP) imaging are required to register the multi-channel images. Secondly, the along-track multi-channel is processed which contains clutter rejection and radial velocity estimation. Thirdly, the cross-track interferometric phase extraction is proposed and 3-D geo-location of moving target is estimated. Apart from extracting height-dimensional information from interferometric phase directly, a method based on digital elevation model (DEM) is also proposed. And the comparison of the two methods is given in this paper. The processing results of real data have confirmed the efficacy and practicality of the proposed algorithm.