FES2004和GOT4.7海潮模型改正对全球PPP的影响特征及差异分析

针对目前少有全球范围PPP海潮负荷影响特征分析的问题，对比FES2004与GOT4.7海潮模型改正前后20个IGS站静态和动态PPP的解算结果，探讨2种模型下的潮波差异。实验结果表明，海潮负荷引起全球沿海站点的U方向位移达5 cm，但在地中海及波罗的海等陆间和内陆海域，并非单纯随站点离海岸线越近位移越大；海潮负荷在世界范围24 h静态PPP中对坐标误差RMS的影响达数mm，改正后收敛时间提升率最高达30%，但在某些岛屿和陆海交界地带对E、N方向的改正效果较差；基于2种模型计算的全球M₂分潮U方向差异在近海区域最大可达13 mm，且地理分布上与海潮本身无必然联系，负荷形变差异具有与海潮类似的周期性特征，在马来群岛附近达数mm，且半日潮差异高于周日潮与半月潮。

Characteristics and Differences Analysis of the Effect of FES2004 and GOT4.7 Ocean Tide Model Corrections on Worldwide PPP

There is currently little analysis of the effect characteristics of ocean tide loading worldwide in PPP, so we compare the solutions of static and kinematic PPP for 20 IGS stations before and after ocean tide model corrections of FES2004 and GOT4.7, and discuss the difference of tide waves under the two models. The test results show that the displacement in the up direction of coastal stations worldwide caused by ocean tide loading can reach 5 cm, but it does not simply increase, as sites are closer to the coastline in intercontinental and inland seas such as the Mediterranean and the Baltic Sea. Ocean tide loading effects on the coordinate error RMS in 24 h static PPP worldwide can reach several millimeters and the upgrade rate of convergence time can reach 30% after correction, but for some islands and land-sea junction zones, the correction effect of east and north directions is poor. The difference of M₂ constituents in the up direction worldwide based on the two models can reach a maximum of 13 mm in offshore areas, and it is not necessarily related to ocean tide itself in terms of geographical distribution; the difference of ocean tide loading deformation has a periodic characteristic similar to ocean tide, which can reach several millimeters near the Malay Archipelago, and difference in half-diurnal tide is higher than that of diurnal tide and half-moon tide.