Doppler Radar tomography of rotated object in noisy environment based on time-frequency transformation

Abstract

The backscatter from radar provides Doppler information of the scatterer giving the frequency characteristics over time, or in the case of rotating objects, over varying aspect angle. These frequency domain projections are used for Doppler radar tomographic imaging. This paper presents a method for imaging of a rotating target using a time-frequency transformation as a tomographic projection. The resolution of a tomographic image depends on the resolution of input projections. The reassigned spectrogram is proposed as tomographic projections, which allow to obtain a clearer image of a rotating object than conventional Fourier-based image formation. The reassigned spectrogram is very sensitive to noise so the denoising procedure on the time-frequency plane must be performed before the reassigned spectrogram transform. The proposed idea of imaging is illustrated on numerical experiments.