Equivalent slant range model for geosynchronous SAR

Abstract

Geosynchronous (GEO) synthetic aperture radar (SAR) has an orbit height of 36 000 km which results in long round-trip time. Thus, the ‘Stop–Go’ assumption and the conventional slant range model for low-Earth-orbit (LEO) SAR lose effectiveness in GEO SAR. A concise signal propagation delay equation of GEO SAR is presented and furthermore an equivalent slant range model is proposed. To verify the accuracy of the proposed model, the dichotomy method is applied to obtain the real slant range. In addition, the effects of the ‘Stop–Go’ assumption on GEO SAR are analysed by theoretical analysis. Promising results were obtained by several experiments.