High-precision, fast geolocation method for spaceborne synthetic aperture radar

Geolocation using spaceborne synthetic aperture radar (SAR) is essential for imagery applications, and high performance geolocation methods need to be developed to promote SAR imagery applications. Starting from the SAR imaging principle, this paper reveals and analyzes two basic characteristics of SAR imaging geometry, and demonstrates the rationality of the two characteristics. On this basis, a high-precision and fast geolocation method is proposed. We conducted a precision analysis on four SAR satellites (Germany’s TerraSAR-X, Italy’s COSMO-SkyMed, Japan’s ALOS-PalSAR and Canada’s Radarsat-2 satellites), and the results show that the precision of the proposed method meets practical needs. We then used TerraSAR-X SpotLight SAR real data to implement the fast geolocation, and found from performance evaluation that the computation cost is greatly reduced while high geolocation accuracy is maintained. We thus verified the efficiency and accuracy of the proposed method.