APPLIED RESEARCH OF MONITORING THE URBAN LAND SUBSIDENCE USING GPS SURVEYING

GAO Wei 1,2 ,XU Shao-quan 1,LIU Ai-tian 3 (1.College of Geodesy and Geomatics,Wuhan University,Hubei Wuhan 430079,China;2.College of lnformation Science and Engineering Shandong Agricultural University,Taian 271018,China;3.Bureall of Land and Resource of Linyi,Linyi 276001,China)

GPS monitoring;land subsidence;tropospheric delay;data processing

Abstract:In order to monitor the change of urban land subsidence by high accurate GPS height surveying technique,a GPS fiducial network were established in N city.Some measures were taken during GPS observation in order to obtain the high precise height component.Considering the affect of tropospheric refraction,Saastamoinen model was adopted in the data processing of the dry component part of the tropospheric delay.The wet component change of the tropospheric delay was estimated by using stochastic processes model.The high precision Bernese software was used to resolve the baselines.And the network adjustment was carried out with PowerADJ scientific research edition.It is verified by the practical example in this paper that the mm-level measuring precision was achieved when the urban land subsidence was monitored using GPS surveying.The precision of GPS surveying canstisfy the reguirement of the wrban land subsidence.