Wideband Time-space Radon-Fourier Transform for High-speed and Weak Target Detection

The Across Range Unit (ARU) effect, mismatch issue in the matched filter and the aperture fill phenomenon can badly deteriorate the performance of high-speed weak target detection in wideband Digital Array Radar (DAR). To address these issues, a novel long-time coherent integration method, namely, Wideband Space- Time Radon Fourier Transform (WST-RFT) is proposed. Based on the 3D echo model of DAR, the system response function of wideband matched filter is given, and by jointly searching the 3D parameter space, the ARU effect, mismatch problem of the matched filter and the aperture fill phenomenon can be simultaneously addressed. Then, the optimality of the WST-RFT based detector is demonstrated. Furthermore, to solve high computation cost problem caused by ergodic search in the WST-RFT, a fast implementation based on Chirp-Z Transform (CZT) is given. Finally, numerical experiments demonstrate the effectiveness of the proposed method.