InSAR联合矢量倾角分段函数模型计算矿区地表下沉量

Calculation method of surface subsidence in mining area based on InSAR and dip angle piecewise function model

针对单轨合成孔径雷达(InSAR)仅能获取沿雷达视线(LOS)向形变和概率积分法(PIM)难以预计沉陷盆地边缘区域下沉量的问题,该文提出了一种由单轨InSAR监测的LOS形变联合移动矢量倾角模型计算矿区地表下沉量的方法。该方法首先在分析下沉盆地地表移动矢量倾角变化特征的基础上,建立主断面上地表点移动矢量倾角的分段函数模型,再结合主断面地表点的LOS向与地表移动矢量的矢量夹角与倾角的函数关系,实现由LOS向形变计算矿区地表下沉量。以马泰壕井田和上湾煤矿的两个工作面为研究对象,采用Sentinel-1A数据和水准实测数据对该方法的可行性和精度进行了验证;结果表明,在沉陷盆地边缘区域,该方法计算的地表下沉量与实测值吻合,两个矿区的监测精度均方根误差(RMSE)都约为5mm,高于InSAR监测精度的19mm,监测精度分别提高了74%和71%。

In view of the deficiency that the single orbit interferometric synthetic aperture radar(InSAR)technology can only obtain line of sight(LOS)deformation and the probability integration method(PIM)is difficult to obtain subsidence in the edge area of the subsidence basin,a method for calculating the surface subsidence of mining area by combining the dip angle model and the deformation monitored by single orbit InSAR was proposed.First,a piecewise function model of the movement vector dip angle based on the analysis of the change characteristics of the movement vector dip angle in the subsidence basin was establishe,and then the functional relationship between the movement vector dip angle and the vector angle was combined,which was the included angle between the LOS direction of the point on the dip main section and the surface movement vector,to calculate the surface subsidence of the mining area from the LOS direction deformation.Taking two working faces in Mattaihao mine field and Shangwan mine as the research objects,then the feasibility and accuracy of this method were verified using Sentinel-1A data and leveling measurement data;The results showed that the surface subsidence in the edge area of the subsidence basin calculated by this method was close to the measured value,and the monitoring accuracy root mean square error(RMSE)was approximately 5 mm,which was higher than the InSAR monitoring accuracy of 19 mm,and the monitoring accuracy had been improved by 74%and 71%respectively.