海潮负荷对中国区域CORS站点精密定位的影响

为了研究海潮负荷对中国区域连续运行观测站精密定位的影响,利用GAMIT软件,采用加入全球海潮模型和不加入全球海潮模型两种解算模式,选取了不同区域的CORS站点和同一区域多天的CORS站点分别进行解算,并对解算结果进行了分析比较。结果表明:海潮负荷位移在海岛上的影响最大,特别是在U方向,达到了厘米级,在N和E方向上的影响相对较小;沿海站点E和U方向上的影响在0.2～0.3 cm之间,N方向上的影响相对较小,而对内陆站点的影响基本可以忽略不计;对于CORS站点连续多天的基线处理,加入海潮模型改正对整体解算精度有一定的改善。所以在高精度定位解算时必须加入海潮模型改正。

Ocean Tidal Loading Effects on Precise Positioning at CORS Sites in China

In order to determine the influence of ocean tidal loading (OTL) on the precise positioning of CORS sites in China,CORS sites in different regions and one CORS site in the same region in a long time span are selected,and the position of these sites are solved by using GAMIT software considering adding the global OTL model or not.The results show that the OTL effects are most significant for CORS sites located on the island,especially in upward direction,even up to cm amplitude.For CORS sites located on the coastal area,the influence of OTL in eastern and upward directions is approximately 0.2~0.3cm.While for inland CORS sites,the influence can be ignored.Solution accuracy of GNSS network is improved when OTL correction is adopted for multi-days base line processing.Therefore,OTL effects should be taken into account in precise GNSS data processing.