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.