基于PSInSAR和GIS空间分析的南通市区地面沉降监测

Ground Subsidence Detection of Nantong City Based on PSInSAR and GIS Spatial Analysis

摘要:

提高永久散射体雷达差分干涉测量(PSInSAR)技术中大气延迟相位提取精度,在采用滤波方法从残余相位中提取大气延迟相位时,提出了基于结构函数的最佳滤波方法及滤波窗口大小的自动确定方法;并对PS(permanent scatterer)点的线性形变速率进行空间分析,了解其数据分布,探测离群值,然后进行Kriging插值,以获得高分辨率的沉降速率图.为验证方法的有效性,以江苏南通市区为试验区域,采用2006—2007年间15幅Envisat卫星SAR(synthetic aperture radar)图像进行地面沉降监测.结果表明,该方法有利于确保大气延迟相位的提取精度,获得了南通市区高分辨率的沉降速率图,发现南通市区存在多个沉降漏斗,但在2006—2007年间没有出现沉降速率特别大的沉降漏斗,大部分区域的沉降速率不超过11 mm·年-1.

Abstract:

The best filter method was proposed and the window size was determined by the structure function to improve the accuracy of extracting the atmospheric effects from the residual phase by filtering in the Permanent scatter interferomentry SAR(PSInSAR)technique.The linear deformation rate of permanent scatterers was analyzed to examine the distribution of data and detect outliers,and then was interpolated with Kriging method.To verify the method,Nantong was chosen as the test area and 15 Envisat SAR images acquired during period of 2006—2007 were used to detect the ground subsidence of Nantong.The experimental results show that the method can improve the accuracy of the extraction of atmospheric effects.A ground subsidence rate map of Nantong with high resolution is generated.Several subsidence funnels are found in Nantong downtown during the period of 2006—2007.There are not large subsidence funnels in Nantong downtown between 2006 and 2007,and the subsidence rate of most regions in Nantong city is no more than 11 mm annually.