A Method of Lunar Mapping SAR Baseline Estimation Without GCPs

Abstract

Baseline error is one of the main error sources that affect the accuracy of InSAR (Interferometric Synthetic Aperture Radar) elevation measurement. When performing DEM (Digital Elevation Model) elevation inversion, high-precision baseline estimation is needed to improve the accuracy of DEM data. This paper proposes a No-GCPs (Ground Control Points) InSAR baseline vector estimation method based on EKF (Extended Kalman Filter). For lunar mapping SAR, it is difficult to obtain elevation control points. This method establishes a function model of the interferometric phase and baseline vector in the reference target region, and traverses and estimates the elevation information of the target region as an unknown quantity. Then, the baseline estimation results are filtered based on the criterion of minimum mean square error, so as to achieve high-precision baseline estimation under the condition of no control points. Finally, the effectiveness of the method is verified by simulation experiments. The results show that the proposed method can achieve high-precision baseline estimation without control points. Key words – InSAR; Control Points; EKF; Lunar Mapping