A Method for Calculating Surface Deformation in Mining Areas by Fusion of Pixel Offset Tracking and Short Baseline Set

Abstract

The invention provides a mining area surface deformation resolving method through fusion of pixel element offset tracking and a short baseline set, and is suitable for the research of surface mining area surface deformation. The method comprises the steps that a mining area surface deformation area is pre-estimated; high-coherence points in coherence images on time sequences are selected; the number N of integer phase cycles of the high-coherence points of a large-deformation area is recovered by utilizing a time sequence offset tracking algorithm; the high-coherence points of the large-deformation area and a small-deformation area are combined to establish a short baseline set resolving model; and resolving of mining area surface elevation error and deformation rate is performed. The method is high in monitoring precision, large in range, simple in implementation operation process and low in cost so that the problem that the conventional time sequence InSAR method cannot correctly acquire surface settlement under large mining area deformation gradient can be overcome, the problem that the time sequence pixel element offset tracking algorithm based on SAR amplitude information and the short baseline set technology based on differential phase are difficult to combine to resolve the surface deformation rate and the elevation error can also be solved, and thus the method has wide practicality.

Description

technical field [0001] The invention relates to a method for calculating surface deformation in a mining area, and is especially suitable for a method for calculating surface deformation in a mining area that combines pixel offset tracking and a short baseline set. technical background [0002] Interferometric Synthetic Aperture Radar (InSAR, Interferometric Synthetic ApertureRadar) has the advantages of all-weather, large coverage, high precision, and penetrating power. It is widely used in terrain mapping, deformation monitoring, and surface parameter inversion. DInSAR (Differential InSAR) is mainly used for surface deformation monitoring, and has great application potential in fields such as volcano monitoring, land subsidence, seismic deformation field acquisition, and landslide monitoring. However, this technology is affected by factors such as time baseline, space baseline, and atmospheric delay. The time-series InSAR method that only processes and analyzes some high-c...

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Problems solved by technology

However, this method first needs to unwrap the differential phase when solving the calculation, and the mining subsidence speed is fast and the deformation is large, so the phase unwrapping can only solve the settlement value of the deformation gradient of adjacent points between (-π, π] , the surface subsidence in the large deformation area is difficult to obtain correctly through the phase unwrapping method, resulting in a small monitoring level in these areas, which is difficult to meet the large deformation monitoring requirements of the mining area

At the same time, the pixel offset tracking algorithm can solve large surface deformation, and is currently mainly used in glacier movement, earthquake deformation, etc., but the accuracy of surface deformation obtained by using SAR amplitude information is low, and it is very time-consuming. The error is not equivalent to the terrain error in the short baseline set technology based on the differential phase, and it cannot be brought into the short baseline set model for direct solution

Therefore, there is currently no method to combine pixel offset tracking and short baseline set to solve surface deformation and elevation error

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