Geolocation analysis for near-space synthetic aperture radar based on Rang-Doppler model

Abstract

Near-space has important strategic significance in both military and civil fields, and it has become a research hotspot. Synthetic aperture radar has the ability of high-resolution imaging in all-weather, all-time and all-weather, which is especially suitable for monitoring in near-space. Precise geolocation is an important preprocessing step for SAR image rectification and application. For near-space, the curvature of the Earth cannot be ignored, and the Range-Doppler model is the preferred method for synthetic aperture radar geolocation. The target position is obtained by solving the Doppler equation, the slant range equation and the modified earth model equation. This paper analyzes the influence of geolocation accuracy for near-space synthetic aperture radar. Firstly, the calculation formulas of the location uncertainty are derived, and then the simulation process and some typical results are given according to the formulas.