Micro-Motion Parameter Estimation of Rotor Targets Based on Image Transformation Method

This paper proposes an image transform method including zero interpolation and Hough transform to estimate the parameters of rotor targets. Firstly, the scattering point echo model of the rotor targets is established to generate the echo signal, and the signal is changed to the time-frequency domain using the short-time Fourier transform (STFT). Considering the Doppler ambiguity when the sampling frequency is lower than the highest frequency in the micro motion signal, the image transform method is used to estimate the parameters; when the Hough transform is used to estimate parameters in the time-frequency domain, there is an error, while inverse Rodon (I-Radon) transform cannot estimate parameters effectively. Therefore, the sampling frequency is expanded by inserting zeros to reduce the parameter estimation error. Theoretical analysis and experimental simulation verify the feasibility and effectiveness of the combination of zero interpolation and Hough transform in the case of Doppler ambiguity.