A new unambiguous radial velocity estimation approach of ground moving targets for SAR system

In this paper, we present an unambiguous radial velocity estimation approach which utilizes the wideband characteristic of the transmitted signal (multi-wavelength). The returned echo of the moving target is compressed in azimuth time and range frequency domain by using the SPECAN algorithm. The corresponding envelope (trajectory) in azimuth compressed time and range frequency domain is a straight line with its slope proportional to the true target radial velocity. Then we estimate the slope and can unambiguously obtain the radial velocity. The effectiveness of proposed method is demonstrated by real measured data.