Ground moving target imaging method study using GNSS-based passive bistatic radar

Passive bistatic radar based on Global Navigation Satellite System (GNSS) is a potential space-based radar system, which has the advantages of low power consumption and good concealment. Due to the low signal power density, it is necessary to increase the target signal-to-noise ratio through long-time integration. However, target motion will cause range migration and Doppler spread, and the traditional pulse doppler radar processing method is no longer applicable. Aiming at this problem, this paper proposes a moving target imaging method based on Radon Fourier transform (RFT). Firstly, by adding the Doppler rate compensation factor to the traditional RFT method, the three-dimensional parameters of the moving target are jointly searched and estimated. And then through parameters compensation to complete the target imaging in the range Doppler domain. This method not only considers the influence of Doppler phase modulation, but also realizes rapid deployment in the range frequency domain, which can achieve a better imaging effect than traditional methods. The performance of the proposed method is verified based on the actual experiment using GPS satellite as the illuminator of opportunity.