Modified Generalized Omega-K Algorithm for Low Earth Orbit High Resolution Spotlight Spaceborne SAR Focusing

Abstract

Algorithms for high resolution spotlight Synthetic Aperture Radar (SAR) focusing typically face challenges of curved orbit and azimuth aliasing. To conquer these difficulties, a novel algorithm, which is named as Modified Generalized Omega-K (MGOK) algorithm, is proposed in this paper for focusing low-orbit high resolution spotlight spaceborne Synthetic Aperture Radar (SAR). The proposed method modifies the Generalized Omega-K algorithm with orbital state vectors and deramping-based approach in order to accommodate the scenario of Low Earth Orbit (LEO) high resolution spaceborne SAR. Experiments are performed on point target simulation for assessing the effectiveness of the proposed method. In simulation, the range and azimuth resolution can both obtain 0.5m with scene size of 4km by 4km.