A method and system for monitoring insar surface deformation based on discontinuous coherence

Abstract

The invention discloses an InSAR surface deformation monitoring method and system based on discontinuous coherence. The method includes: obtaining the surface SAR image of the monitored area; registering the SAR image; extracting the interference pair in the SAR image by using the small baseline set method; performing differential interference processing on the interference pair; The points include continuous coherent points that maintain high coherence continuously in the time series and intermittent coherent points that maintain high coherence intermittently in the time series; phase unwrap the coherent points; determine the coherent points based on the unwrapped phase of the coherent points The linear deformation of the coherent point; subtract the linear deformation phase of the coherent point from the unwrapped phase of the coherent point to obtain the residual phase; filter the residual phase to obtain the nonlinear deformation of the coherent point; synthesize the linear deformation of the coherent point and Non-linear deformation, which determines the deformation or deformation rate of the surface of the monitored area. The invention can effectively monitor the regional deformation of intermittent coherent points in time series.

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...

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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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