Time-frequency transform used in radar Doppler tomography

The paper focuses on the radar imaging for a rotating object using tomographic method. The simplified mathematical model of radar returns from one rotating scatterer is used for generating of radar projections required in tomographic imaging. These projections are strictly connected with micro-Doppler phenomena and give the frequency characteristics over time. Doppler radar tomography imaging is performed in the narrow-band radar. The modulus of the Short Time Fourier Transform of radar returns is proposed as radar projections. It is experimentally shown on the simulated data, that applying the reassigned spectrogram nearly smear-free projections could be obtained. So the reassigned Short Time Fourier Transform looks promising as projections. Next the back projection algorithm is applied to reconstruct the image in order to get the spatial location of the rotating point using simulated projections. High-resolution radar image strongly depends on smear-free projections so methods for improving the projections are intensively explored.