不同海潮模型对东南极沿海地区GPS基线解算的影响

在高精度GPS数据处理中,海潮的影响是一个不可忽略的因素。利用GAMIT软件解算2011年东南极沿海地区中国中山站及其周边6个IGS站的GPS数据,对比分析了FES2004、DTU10、EOT11a、GOT4.7、HAMTIDE11a、OSU12以及TPXO7.2等7个全球海潮模型在不同测站的海潮负荷差异,比较了海潮负荷对于GPS基线解的影响。结果表明,海潮负荷对GPS基线解的影响与测站所处位置及基线方位有关,达到cm级,相对影响达到10-8,因此,在高精度的GPS基线解算中必须考虑海潮的影响;但选用不同海潮模型对东南极沿海地区GPS基线解算的差异可忽略不计。

Effects of Different Ocean Tide Models on GPS Baseline Solutions in Coast Area,East Antarctica

Ocean tide loading(OTL), which is usually computed from an ocean tide model, is a factor that cannot be ignored in high accuracy GPS data processing. Due to the lack of highly accurate altimetry data and the presence of sea ice, the polar region is one of the regions where ocean tide model has the lowest accuracy in the world. To show the intermodel discrepancies on polar regions and the effect of OTL on GPS baseline solutions, the OTL computed by seven different models (FES2004, DTU10, ETO11a, GOT4.7, HAMTIDE11a, OSU12, and TPXO.7.2) at Zhongshan and six other IGS stations in the coastal area of East Antarctica were calculated, and the effects of these seven models on GPS baseline solutions were compared using GAMIT software. The results show that, the effect of OTL on GPS baseline solutions was subjected to the station locations and baseline directions, and can reach centimeter level and 10-8 for absolute and relative accuracy, respectively. The effects of OTL must be considered during high accuracy GPS data processing. The effects of OTLs computed from different ocean tide models on GPS baseline solutions for the coastal area of East Antarctica are not significant and can be disregarded.