A GMTI Method for Near-Space Hypersonic Vehicle-borne SAR based on Track Before Detect in Image Domain

Ground Moving Target Indication (GMTI) for Near-space Hypersonic vehicle borne Synthetic Aperture Radar (NH-SAR) is an important part of remote sensing applications. However, the ultra-long range and the ultra-high flight speed of NH-SAR causes the lower echo signal-to-noise ratio (SNR) and the expanded clutter spectrum, which reduces the performance of traditional GMTI methods such as Displaced Phase Centre Antennas (DPCA), along track interferometry (ATI) and Space Time Adaptive Processing (STAP). In this paper, a method based on Track Before Detect (TBD) in image domain is proposed to perform GMTI for NH-SAR. This method obtains the multi-frame images of NH-SAR firstly, and tracks the trajectories of the moving targets in the images. The simulation results validate the effectiveness of the proposed method, and show that this method has lower false alarm probabilities under the low-SNR condition.