A Joint Compensation Method for Repositioning Error and Atmospheric Phase Screen of Ground-Based SAR

In the monitoring of discontinuous ground-based synthetic aperture radar (GB-SAR), challenges such as repositioning error and atmospheric phase screen (APS) can significantly impact the accuracy of deformation inversion. Existing compensation methods are limited to specific scanning modes (linear-scanning or arc-scanning) and lack a unified framework, leading to suboptimal performance in complex scenarios. We propose a novel joint compensation model applicable to both linear-scanning and arc-scanning GB-SAR. By formulating repositioning error as ternary functions of positional shifts and linearizing them through first-order approximation, the method establishes a unified phase error model. A high-order range error component is integrated to characterize APS effects. The combined model parameters are optimized by gradient descent. Experimental validation using near-field and far-field datasets demonstrates significant improvements: in linear-scanning mode, the residual phase RMSE is reduced by 40.4%, while arc-scanning mode it decreased by 6.8%. The proposed framework effectively compensates for two errors, outperforming conventional approaches by unifying compensation across scanning geometries. This study enables high-precision deformation monitoring in diverse GB-SAR applications, advancing the reliability of geological hazard early warning and infrastructure assessment.