中文摘要：

根据海潮负荷理论，利用4种全球海潮模型分别计算了中国及周边地区IGS站的海潮负荷位移系数，分析并比较了海潮负荷位移对GPS单天解和短周期解的影响。结果表明，对于测站的单天解，不同海潮负荷位移改正对测站整体上没有影响，只在局部沿海地区测站的垂向方向存在差异；并且，4种全球海潮模型在黄海和东海的近海区域不够精确，需要利用我国近海区域的海潮资料进行修正；对于测站的短周期解，海潮负荷位移的影响随着测站远离海洋而减弱，特别是在沿海地区能显著提高测站的垂向坐标精度。因此，在短时的GPS精密定位中需要考虑海潮负荷位移改正。

英文摘要：

Ocean tide loading has a crucial geophysical effect on GPS precise positioning. Based on the theory of ocean tide loading, ocean tide loading displacements for IGS stations in China and surrounding areas resulting from four global ocean tide models are calculated, and their influences on GPS daily and sub-daily solution are analyzed and compared. For daily solution for the station, results show that ocean loading displacement corrections lead to the same RMS for the daily solution residuals with no corrections on average, but for RMSs of daily solution residuals in the vertical direction, there are changes in coastal areas, so it is believed that four ocean tide models have insufficient accuracy for the offshore area of the Yellow Sea and the East China Sea, and must be corrected by the data for the China offshore regional ocean tide. For sub-daily solutions for the stations, results show that the ocean tide loading effect decreases with the distance of the station from the sea. Particularly in coastal areas, the accuracy of the vertical coordinates of the station can be significantly improved, so ocean tide loading displacement corrections should be considered in sub-daily GPS precise posmonlng.