Joint Detection of Moving Target Based on Distributed Video SARs

High resolution and high frame-rate radar imaging is of great significance for ground moving target indication (GMTI). However, the traditional video synthetic aperture radar (SAR) is not conducive to detecting high-speed target at long distance due to high frequency and long synthetic aperture. This paper proposes a new moving target multi-dimensional joint detection method for distributed video SARs based on the swarm unmanned aerial vehicles (UAVs). First, equivalent long synthetic aperture and displaced phase center antenna detection channels can be obtained by using the short synthetic apertures formed by each UAV in different time and spaces, which can realize high frame-rate imaging in the lower frequency and shorter integration time, leading to clear moving target shadow and focused moving target image. Second, the moving target state can be initialized by pre-detection after clutter suppression and velocity matching. Third, a dynamic programming-based track-before-detect (DP-TBD) algorithm is used to realize joint accumulation of multi-dimensional moving target information based on state mapping between shadow and energy. Finally, a shadow-aided radial velocity estimation method is adopted, which can effectively determine the ambiguity number of the interference phase. The proposed approach can significantly improve the detection performance of high-speed targets.