Parameter Estimation of Ground Moving Targets Based on SKT-DLVT Processing

It is well known that the motion of a ground moving target may induce the range cell migration, spectrum spread, and velocity ambiguity during the imaging time, which makes the image smeared. To eliminate the influence of these factors on image focusing, a novel parameter estimation algorithm for ground moving targets, namely SKT-DLVT, is proposed in this paper. In this method, the segmented keystone transform (SKT) is used to correct the range walks of targets simultaneously, and a new transform, namely, Doppler Lv's transform (DLVT) is applied on the azimuth signal to estimate the parameters, i.e., the along- and cross-track velocities of targets. Theoretical analysis confirms that no interpolation is needed for the proposed method and targets can be well focused within limited searching range of the ambiguity number. The proposed method is capable of obtaining accurate parameter estimates efficiently in low signal-to-noise ratio (SNR) scenario with low computational burden and memory cost. Thus, it is suitable to be applied in memory-limited and real-time processing systems. The effectiveness of the proposed method is demonstrated by both simulated and real data.