A Novel HRWS Imaging Algorithm with Velocity Compensation for Spaceborne Multi-channel SAR

Abstract

In Spaceborne Synthetic Aperture Radar (SAR), the equivalent velocity of radar varies with range. When classic $\omega-k$ algorithm is used to process spaceborne data, the farther distance from reference range, the worse azimuth focusing quality will limit the width of swath greatly. In this paper, an improved $\omega-k$ algorithm is proposed to solve the imaging in high resolution wide swath (HRWS) SAR, the key idea of which is to realize equivalent velocity compensation from the received ground echoes by using the Contrast Optimization Autofocus (COA) to estimate the equivalent velocity. The experiment demonstrates that the improved algorithm can process the wide swath spaceborne SAR data accurately and effectively.