Study on high-speed and multi-target detection algorithm based on STFT and FRFT combination

Using radar to detect multiple high-speed targets is a process that can be equivalently expressed by detection of multiple linear frequency modulation signals. In this paper, preliminary detection is performed on multiple signals using short-time Fourier transformation (STFT) and then the preliminary detection results are treated using binaryzation, during which the phase information of the signals are preserved. Then, detection is made using fractional Fourier transformation. The combination of the two techniques is advantageous because the phenomena of strong signal side lobe suppressing weak signal main lobe is avoided and the signal-noise ratio (SNR) of the to-be-detected signals is improved. Meanwhile, image contrast and successive elimination are introduced in target isolation process, which helps increase the utilization of signals in space and frequency dimensions, with the result that the detection probability of target signals are further enhanced.