An accurate range model of moving target based on mth-order Taylor expansion for GEO SAR

Abstract

Considering that Geosynchronous Earth orbital Synthetic Aperture Radar (GEO SAR) allowing a wide area viewing combined with short revisit cycle, it is suitable for many applications such as natural disaster monitoring, military reconnaissance and soil moisture detection. In this paper, a novel method for calculating the precise propagation distance of moving target in GEO SAR is proposed. This method mainly solves the following two problems: 1) Existing low-order Taylor expansion range model shows insufficient accuracy under ultralong integration time. 2) The iterative approximation range model has high accuracy but cannot be expressed by analytical expression. By deriving the general formula of the mth-order Taylor expansion of pulse transmitting and receiving distance, a complete set of processes to calculate the total propagation distance is formed, and the expansion order can be adjusted according to the error requirement. Finally, a series of simulation experiments have been conducted to verify the fitting effect of the new range model.