Discontinuous coherence-based InSAR earth surface deformation monitoring method and system

Abstract

The invention discloses a discontinuous coherence-based InSAR earth surface deformation monitoring method and system. The method comprises the steps of acquiring an earth surface SAR image of a monitored region; registering the SAR image; extracting an interference pair in the SAR image by a small baseline subset method; performing differential interference processing on the interference pair; extracting a coherent point in the interference pair, wherein the coherent point comprises a continuous coherent point and a discontinuous coherent point, the high coherence of the continuous coherent point is continuously maintained on a time sequence, and the high coherence of the discontinuous coherent point is discontinuously maintained on the time sequence; performing phase unwrapping on the coherent point; determining linear deformation of the coherent point according to a phase of the coherent point after phase unwrapping; subtracting a linear deformation phase of the coherent point from the phase of the coherent point after phase unwrapping to obtain a residual phase; filtering the residual phase to obtain non-linear deformation of the coherent point; and summarizing the linear deformation and the non-linear deformation of the coherent point, and determining deformation or deformation rate of an earth surface of the monitored region. By the method, the regional deformation of discontinuous coherent point location on the time sequence can be effectively monitored.

Description

technical field [0001] The invention relates to the technical field of microwave remote sensing, in particular to an InSAR surface deformation monitoring method and system based on discontinuous coherence. Background technique [0002] InSAR is an active microwave radar detection technology. It has technical advantages such as large scale, low cost and high precision. In recent years, it has shown great potential for deformation monitoring in many fields, such as landslides, glacier movement, land subsidence, etc. The conventional Differential SAR Interferomtry (DInSAR) technology calculates the deformation by making a difference between two images, but because DInSAR technology is affected by the phenomenon of decoherence, the current research on InSAR technology in the world mainly focuses on long-term sequence DInSAR technical research. The long-time series DInSAR is significantly different from the traditional DInSAR. It mainly analyzes the points with stable phase an...

AI Technical Summary

Problems solved by technology

However, this method can only monitor areas that maintain high coherence in the time series, such as urban areas, exposed rocks, and large man-made facilities.

It is invalid for low coherence value areas (vegetation), which cannot completely reflect the deformation area, which makes it difficult for subsequent deformation interpretation

Due to the influence of human activities, geological activities and geological environment, such as seasonal vegetation coverage, soil moisture and climate change, etc., the physical characteristics of the surface will be suddenly changed, reducing the coherence of the interferogram, causing these pixels to be interrupted in the time series Coherence, although such points contain deformation information in the time series, they are not considered in the traditional SBAS technology, so that the distribution of points in low coherence areas is less, so that the deformation information in these areas cannot be correctly reflected

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