Algorithm on the Estimate of Residual High-Frequency Motion Error in Synthetic Aperture Radar

Abstract

In this article, the estimate of high-frequency phase error (HPE) induced by residual motion error (RME) is studied for synthetic aperture radar (SAR). The proposed algorithm contains two basic procedures. First, according to the pair-echoes caused by HPE, the frequency coefficients could be estimated by mean filter. Second, the estimate of the amplitudes and initial phases could be accomplished by the parametric or nonparametric autofocus manners. The sharpness metric (SM) is used in the parametric manner, while the notch filter (NF) and phase gradient autofocus (PGA) are performed in the other one. For the excessive range migration (ERM), the reflectivity displacement method (RDM) and range resolution degradation are adopted to eliminate it. Finally, the simulated and real data experiments show that the proposed algorithms are valid.