Analysis of Effective Slant Range Model Accuracy Based on Low-Earth-Orbital (LEO) Spaceborne SAR

This paper aims at analyzing the applicability of the hyperbolic range model meeting resolution higher than one meter for low-earth orbital spaceborne SAR. How long the integration time can the range model be applied to, and the corresponding azimuth resolution are main issues of this paper. An accurate geometry is modeled firstly to get the Doppler centroid and the Doppler FM rate, which have the higher accuracy. Then the accurate range model can be got through the Doppler parameter reversion. The azimuth history phase errors can then be calculated by comparing with the numeric values of the slant range information. If the errors are under the threhold of ,/4 the disfocusing is impossible. Based on the theory above, the parameters of TerraSAR-X are utilized for simulation. The longest integration time and the best resolution got from the hyperbolic range model are analyzed. The conclusion of this paper offers an approach for analyzing the range model of the current low-earth orbital spaceborne SAR.