A phase unwrapping method and system for gb-sar monitoring of dam and landslide deformation

Abstract

The invention provides a phase unwrapping method and system for GB-SAR monitoring of deformation of dams and landslides. The method includes: acquiring GB-SAR interference images in the deformation monitoring area, selecting N PS points with stable phases, and performing One-dimensional time phase unwrapping to obtain the time phase unwrapped interferometric phase value Use the selected PS points to construct a Delaunay triangulation, and calculate the double-difference phase observations of M edges in the triangulation Based on the indirect least squares adjustment method, construct the error equation The error equation of M sides is transformed into a matrix expression to establish the method equation A T PA‑A T PL=0, then Φ=(A T PA) ‑1 A T pl. The invention proposes a phase unwrapping method for the GB-SAR monitoring system of dams and landslides in alpine valleys, which reduces the influence of atmospheric disturbance on the unwrapping accuracy; avoids integrating by "passing through" residual points, and will not transfer The error greatly improves the unwrapping accuracy; the global solution method is used to speed up the convergence speed and make the unwrapping process faster.

Description

technical field [0001] The invention relates to the field of GB-SAR interference monitoring, in particular to a phase unwrapping method and system for GB-SAR monitoring of deformation of dams and landslides. Background technique [0002] Ground-Based Synthetic Aperture Radar (Ground-Based Synthetic Aperture Radar, GB-SAR) is a technology that has been widely used in the field of surface micro-deformation monitoring in the past ten years. It can provide thousands of kilometers of remote monitoring, and the deformation data has continuous spatial coverage. In the process of all-day monitoring, high temporal and spatial resolution and high-precision results can be obtained, which is conducive to accurate judgment of the nature, scope and disaster process of disaster deformation. It has become an effective supplement to spaceborne SAR and traditional monitoring methods. [0003] Phase unwrapping refers to the process of restoring the main phase value or interferometric phase di...

AI Technical Summary

Problems solved by technology

The problem is that unwrapping islands may be generated, causing some points to be unwrapped normally. At the same time, there will be a problem that the branch tangent line is not the shortest. Its efficiency is low and the effect is not very ideal.

[0004] The above methods are all proposed based on the basis of In-SAR rather than GB-SAR. Therefore, although their principles have something in common, their unwrapping effects may vary greatly due to the different environmental influences on the observation equipment.

For the GB-SAR monitoring phase of dams and landslides in alpine valleys, it is greatly affected by the environment, climate changes have a strong impact on the signal, and the spatial correlation of the atmosphere is very strong. Therefore, In-SAR is directly used The unwrapping effect of the phase unwrapping method is not ideal

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