Joint Intra-Frame and Inter-Frame Integration Method for High Speed Weak Target Detection

High-speed moving targets with weak radar echoes have recently received more and more attention in the radar detection field. Many intra-frame accumulation algorithms have been proposed to effectively accumulate the target energy in a single frame, but for some weak targets, it is difficult to highlight the target energy using only the intra-frame accumulation algorithm, which implies that the inter-frame integration operation is also needed. However, the existing inter-frame accumulation algorithms suffer from accumulation performance losses due to process noise and range walk (RW). To this end, we first establish the target’s multi-frame signal model including RW and process noise, and then use Radon-Fourier transform (RFT) to accumulate the target energy in each frame. Through the analysis of the output characteristics of the RFT, we obtain the position transfer relationship and phase differences change of the target peak in different frames. On this basis, we propose a tracking-before-detection algorithm in the range-velocity domain by dynamic programming (RV-DP-TBD), which effectively realizes the coherent accumulation of RFT peak energy among frames. The superiority of the algorithm is verified by simulation experiments.