Blind Source Separation-Based High-Speed Weak Target Coherent Detection Method Under Strong Target BSSL Covering Situation

Abstract

The Radon Fourier transform (RFT) is a commonly utilized method in high-speed weak target detection, which can effectively achieve coherent integration (CI) in the presence of migration through range cell. However, the blind speed side-lobe (BSSL) phenomenon may appear in RFT outputs because of discrete pulse-sampling, restricted range resolution and confined CI period. For the case that scattering intensities of multiple targets differ significantly, the side-lobe of the strong target may conceal the main-lobe energy of the weak one and then result in loss detection. To obtain effective coherent detection for weak target, this article proposes a novel weak target coherent detection method under strong target BSSL covering condition based on blind source separation. This method applies the RFT to obtain the outputs mixing of strong and weak target energy at first. Then, constructing the strong target RFT response from the position of its main-lobe. Finally, the BSS is used to process the strong target RFT response and mixing RFT outputs, effectively cleansing the side-lobes of the strong target RFT response and retaining the weak target RFT response. At this moment, the high-speed weak target detection results can be achieved. The efficacy of the proposed method is confirmed by simulation experiments and measured data processing.