Repositioning Error Compensation in Discontinuous Ground-Based SAR Monitoring

Abstract

The discontinuous mode of ground-based synthetic aperture radar (GB-SAR) is suitable for monitoring creep landslides. However, the instrument needs to be installed and disassembled repeatedly, which could inevitably cause repositioning error, and severely affect the accuracy of deformation measurements. This paper performs a detailed theoretical analysis of the repositioning error based on the Taylor expansion of a ternary function, and it can be built as a linear multi-parameter model. Simulations are made to validate the effectiveness of this model compared with two common first-order and second-order models. Then a compensation method based on the permanent scatterer (PS) technique is proposed. Two experiments of discontinuous monitoring are discussed. The first one is an equivalent discontinuous experiment, which utilizes two corner reflectors to evaluate the compensation accuracy. The other one is a discontinuous experiment taken on a steep mountain. Compared with the common methods, the proposed method can better compensate for the error phase and benefit high-precision deformation monitoring.

Radar Interferometry for Urban Infrastructure Stability Monitoring: From Techniques to Applications

“…Although utilizing a fixed station for a ground-based radar can effectively mitigate the baseline errors, resetting up the instrument in the case of using a tripod may still result in baseline errors [105,106]. To address this issue, various studies have been conducted to model the errors in a solution [107,108].…”

“…This is especially vital when dealing with extensive study areas with large SAR datasets. In addition, precise repositioning of the GBRI system is also essential for long-term deformation monitoring as discussed in Section 2 [105,106,219]. If the instrument pillar cannot be built to maintain a stable observation position, it is very important to develop repositioning error correction methods to ensure accuracy.…”