Scanning Error Compensation in Ground-Based ArcSAR Monitoring

Ground-based arc-scanning synthetic aperture radar (GB-ArcSAR) can perform 360° scanning and has a large field of view. Based on the differential interferometry technique, GB-ArcSAR can be utilized to measure the surface deformation. However, affected by the rotating motion, rescanning angle error and rotation center offset during repeated scanning could occur. Through theoretical analysis, this article proves that the rescanning angle error has nearly no effect on the interferometric phase and can be negligible. The phase error caused by the rotation center offset can be built as a linear multiparameter model based on the multivariate Taylor expansion. Simulations are made to analyze the effect of the rotation center offset. A compensation method based on permanent scatterer technology is proposed, by using the least squares method, which jointly compensates the rotation center offset error and the atmospheric phase disturbance error. The compensation performance of the proposed method is validated in different scenarios, which can effectively improve the accuracy of deformation measurement.