Dim moving target detection method based on time-frequency analysis

For it is hard to remove clutters, especially the clutter edge, with conventional high-pass filters in spatial or temporal domain, a dim moving target detection method based on the time-frequency characters of target, noise and clutter is presented. Theoretical analysis shows that the magnitude at the target location in time-frequency domain is a small wave packet, whose magnitude is consistent with the target amplitude, and width is inversely proportional to target speed; the magnitude at clutter edge in time-frequency domain is an uphill or downhill. This target detection method uses two-stage filtering to detect dim target. At first, a threshold based on false alarm ratio criteria in time-frequency domain is adopted to remove noise, and then the energy ratio between main lobe and side l