Imaging characteristic for large elliptical orbit SAR

Abstract

The imaging characteristics of large elliptical orbit synthetic aperture radar (SAR) are different from those of conventional circular orbit SAR because of its large eccentricity. For the first time, the imaging characteristics and algorithms of large elliptical orbit SAR are studied. Firstly, the imaging characteristics of large elliptical orbit SAR are analyzed, such as spatial geometry, ground beam footprint, time-varying satellite velocity, time-varying Doppler characteristics, time-varying synthetic aperture time and time-varying azimuth resolution. On this basis, an elliptical orbit SAR imaging algorithm is proposed, and the echo signals at different orbital positions are imaged using back projection (BP) algorithm. The simulation results show that the imaging characteristics of large elliptical orbit SAR are different from those of conventional circular orbit SAR and BP algorithm can be applied to elliptical orbit SAR imaging processing.