An unambiguous radial velocity estimation method based on interferometric phase in range frequency domain

In this paper, a new unambiguous radial velocity estimation approach in SAR/GMTI system based on interferometric phase in range frequency domain is proposed. An extra Fourier transform after pulse compression in range is added to obtain the linear relationship between interferometric phase and range frequency. The linear slope of range frequency and interferometric phase is used to estimate radial velocity. Since wrapped phase has no effect on the slope, the method is independence of phase wrapping. To improve performance, least square based linear fitting method is used to calculate the slope. Application on the case of clutter background is also analyzed, and Displaced Phase Center Antenna (DPCA) method is used to suppress clutter. Both simulated and real data experimental results demonstrate the effectiveness of the proposed method.