Improved slant range model and imaging method for geosynchronous SAR

Synthetic aperture radar on geosynchronous orbit (GEOSAR) can realize the continuous image on the larger coverage area in the short revisit period of nearly 24h. The four-order slant range model based on the “stop-and-go” supposition for the curve track has been proposed in the some literatures. Owing to the high attitude and the wide swath of GEOSAR, effect of the signal propagated delay and range displacement of point target on the slant range model can lead to the defocused imaging results. Hence, in this paper, we firstly infer the advance slant range model using Taylor expansion considering to the path delay and the position of point target. Then, we deduce the point target two dimensional frequency spectrum and the improved CS imaging method based the above range model. Finally, the correctness of the CS imaging method based on the improved slant range model is verified by the simulation.