Estimating ambiguity number of radial velocity for ground moving targets from a single SAR sensor

This paper addresses an ambiguity number estimation approach of cross-track velocity for ground moving targets from a single synthetic aperture radar (SAR) sensor. We first transform the target signatures into range frequency domain and then compress it for each range frequency. The resulting compressed envelope exhibits a straight line with its slope just proportional to the ambiguity number of the induced Doppler centroid. Then we can estimate its slope and accurately obtain this number by linear features detection techniques. And thus the true radial velocity can be completely retrieved. For dim moving targets, an improved estimation strategy is introduced. The effectiveness of this approach is demonstrated by theoretical analysis and real measured SAR data.