Analysis of two-dimensional spectrum for geosyncheronous SAR

Geosynchronous orbital synthetic aperture radar (GEOSAR) can provide the continuous imaging on the larger coverage area in the short revisit period of nearly 24h. However, the difficulties in the GEOSAR imaging process are curve trajectory and the delay effects mainly stem from the path delay and the atmospheric delay. The curve track problem has been perfectly solved by using the method of Taylor expansion. Nevertheless, the total delay is often ignored, causing the incoherent superposition of GEOSAR echoes and the defocusing imaging results. In this paper, the two-dimensional point target spectrum is deduced based on the above all GEOSAR properties. And the validity of the spectrum is validated well by the simulation of the point target imaging.