A Method of Monitoring Absolute Surface Deformation in Subsidence Area Using Lifting Rail Insar Without Ground Assistance

Abstract

The invention discloses a method for monitoring absolute earth surface deformations of a depression area by means of a rising rail InSAR and a falling rail InSAR without ground support. The method comprises the steps that relative earth surface deformation measured values of the earth surface in two different slope distance directions are obtained by means of data of the rising rail InSAR and data of the falling rail InSAR; relative deformations of the earth surface in the vertical direction and in the longitudinal direction are estimated by fusing relative deformation fields of the rising rail InSAR and the falling rail InSAR; absolute offsets of the relative deformation measured values of the rising rail InSAR and the falling rail InSAR are calculated by means of ground points of which relative deformation magnitudes in the longitudinal direction are smaller than a certain threshold; the absolute deformations of the earth surface in the vertical direction and in the longitudinal direction are estimated by means of the rising rail InSAR deformation value and the falling rail InSAR deformation value which are corrected through the absolute offsets. The technique bottleneck that a traditional InSAR only can obtain the relative earth surface deformations is broken through, and the absolute deformation results of the earth surface in the vertical direction and the longitudinal direction can be obtained without laying ground control points or assuming a far field deformation to be zero.

Description

technical field [0001] The invention belongs to the field of geodetic surveying based on remote sensing images, and in particular relates to a method for monitoring absolute surface deformation in a subsidence area using a lifting rail InSAR without ground assistance. Background technique [0002] Synthetic Aperture Radar Interferometry (InSAR) technology is a space geodetic and remote sensing method developed in recent decades. It is used for monitoring surface deformation caused by geological disasters such as earthquakes, volcanic eruptions, glacier drift, landslides, and debris flows. Especially with the increasing maturity of multi-temporal InSAR technology (such as permanent scatterers and short baseline set technology), it is possible to conduct joint analysis on the time-series SAR images acquired in the same orbit, thereby better suppressing the terrain residual in the InSAR interferogram , Atmospheric delay and loss of correlation noise, etc., further improve the ...

AI Technical Summary

Problems solved by technology

Obviously, this method cannot obtain the absolute deformation results of the surface for the case where the deformation affected area is large and the stable point cannot be found. For details, see reference [3]

[0004] From the above analysis, it can be seen that for areas without ground control points, and the influence range of the surface deformation exceeds the coverage of the entire SAR image, then the existing methods cannot obtain the absolute deformation results of the ground surface

In practice, the above situation is very common. For example, in the face of large-scale land subsidence caused by the exploitation of underground fluids and mineral resources, and when the permafrost produces seasonal vertical deformation due to frost heaving and thawing, it is often difficult to The situation where available ground control points or stable points are found, resulting in the monitored deformation results not truly reflecting the ground subsidence

Especially with the popularization of high-resolution SAR data in recent years, the resolution of InSAR deformation field is getting higher and higher, but the coverage area is getting smaller and smaller, which makes the limitation of InSAR technology more prominent.

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