Analysis of human radar echo signal using warped discrete fourier transform

Abstract

Use of the warped discrete Fourier transform for the time-frequency analysis of the signal on the audio-output of pulse-Doppler radar is examined in this research. The discrete Fourier transform is calculated in points in z-plane that are equidistantly distributed on the unit circle, while the warped discrete Fourier transform is calculated in points that are unevenly distributed on the unit circle. The time-dependent warped discrete Fourier transform for the analysis of the simulated and measured radar signals from a walking human was applied in this research. The results of the time-frequency analysis of radar signals using this transformation are compared with the spectrogram. The results show that the application of the warped discrete Fourier transformation in the radar signal analysis provides a higher concentration of energy around the central Doppler frequency comparing to the spectrogram.