基于虚拟参考站的GNSS滑坡变形监测方法及性能分析

Landslide Deformation Monitoring Method and Performance Analysis Based on GNSS Virtual Reference Station

全球导航卫星系统(global navigation satellite system,GNSS)技术在大坝、桥梁、滑坡等形变监测领域应用广泛。针对传统监测方法需要架设基准站、导致监测成本增加的问题,提出一种基于虚拟参考站的GNSS变形监测方法,利用连续运行参考站(continuously operating reference stations,CORS)观测数据,生成虚拟参考站(virtual reference station,VRS)代替实体参考站,实现高精度变形监测。利用中国云南省屏边苗族自治县约30处滑坡监测点进行实验分析,结果表明,当CORS基准站间距小于40 km时,双差对流层和电离层延迟模型内插精度优于10 mm,利用观测时长大于8 h的数据,可以实现平面精度优于5 mm、高程精度优于10mm的形变监测。

Objectives:Global navigation satellite system(GNSS)technology is widely used in deformation monitoring such as dams,bridges,and landslides.In traditional monitoring methods,the reference stations need to be built,which leads to the increased monitoring cost.Methods:This paper proposes a GNSS deformation monitoring method based on virtual reference station(VRS),which uses the existing continuously operating reference stations(CORS)observation data to generate VRS instead of physical reference station to achieve high accuracy deformation monitoring.Firstly,the existing CORS observation data are used to obtain the atmospheric error correction models and generate VRS.Secondly,the baselines between VRS and each monitoring point are calculated.In order to further improve the accuracy of data processing,Delaunay triangulation networks are formed,and the baseline vector solution results are checked according to the criterion that the triangle closure error is zero.Finally,the checked baseline solution results are adjusted to obtain the final three-dimensional position coordinates of the monitoring points.Results:This paper uses about 30 monitoring points in Pingbian Miao Autonomous County,Yunnan Province for experimental analysis.The results show that the interpolation accuracis of the double-difference tropospheric and ionospheric delay are better than 10 mm if the distance between CORS reference stations is less than 40km.The observation data longer than 8 hours can realize deformation monitoring with horizontal accuracy better than 5 mm and vertical accuracy better than 10 mm.Conclusions:The proposed method can realize the practical application of landslide monitoring.In the future,we can study how to improve the atmospheric error model and further improve the accuracy of data processing.