Study On Effect Of Ocean Tide Loading On GPS Measurement And Its Regional Model

Ocean tide loading can cause deformation of ground station, especially in thecoastal areas, the impact on the vertical direction can be centimeter level and can’t beignored in the high precision measurement. This paper studies the effect of ocean tideloading on high precision measurement such as station, GPS baseline, the zenith delaybased on coastal IGS stations, and analyses the function of offshore, the offshoreregional tidal model is constructed based on Jason-1satellite altimetry data, and thismodel can improve the precision of global model in close to shore, finally detect theocean tide loading influence characteristic with GPS precise point positioningtechnology. The main research content is as follows:(1)This paper first studies the effect of ocean tide loading on station withFES2004and NAO99b tidal model and different earth model based on Chinese inlandand coastal IGS station, the results show that the effect of ocean tide loading oncoastal station can be centimeter level, is generally3to4times that of inland station,and is mainly manifested in the vertical direction, present a certain periodicity, thedifference between ocean tide models in coastal station is millimeter level, and thedifference between different earth model is small.(2)I study the effect of ocean tide loading on GPS baseline, and then calculate theeffect of ocean tide loading on the zenith delay with the GAMIT software, and studythe offshore effect on the calculation of ocean tide loading with the SPOTL software,the results show that the ocean tide loading effects on GPS baseline is similar to theinfluence of the station, also present a certain periodicity, the relative influence isabout10-8; ocean tide loading effect on the zenith delay in the coastal station is larger,can be more than10mm, the difference between models is no more than2mm; thecalculation results difference of main constituent before and after offshore modelcorrection is obvious, mainly reflected in the coastal areas.(3)I extract the tidal information of intersection in Chinese offshore area withharmonic analysis method based on about6years of Jason-1satellite altimetry GDRdata, and construct the regional ocean tide model, and compare it with the tide stationdata and FES2004global ocean tide model, the difference of partial tide amplitude iswithin3cm, reflects good compliance.(4)Take coastal station as an example, get the station coordinate change sequencewith PPP method through the Bernese software, then get the effect characteristics of ocean tide loading with spectrum analysis, and compare it with the result of modelcalculation, the results show that the GPS technology can detect the periodic term ofmian constituent waves, but it is not precise enough.