新西兰海潮负荷位移建模精度分析

为评价新西兰海潮负荷位移建模精度，利用新西兰189个GPS站11 a的实测数据，基于静态精密单点定位测定8个半日潮波及周日潮波的海潮负荷位移参数，并将其与7种全球海潮模型及4种地球模型计算的海潮负荷位移改正值进行比较。结果表明：1）TPXO7.2模型负荷位移改正值与GPS解算的海潮负荷位移参数最符合，M2、N2、O1和Q1潮波均方根误差在水平方向小于0.5 mm，垂直方向小于0.7 mm；2）不同地球模型对确定海潮负荷位移的影响主要体现在M2和N2潮波；3）GPS估值和海潮模型值之间的残差矢量呈现出大小及方向上的区域一致性，部分站点异常的残差值可能反映出当前SNREI地球模型的缺陷。

Modeling Accuracy Analysis of Ocean Tide Load Displacement in New Zealand

In order to evaluate the modeling accuracy of ocean tide load displacement in New Zealand,we use the observations collected from 189 GPS stations in New Zealand with the time span over eleven years.Then,the ocean tidal loading(OTL)displacements at 8 major(diurnal and semi-diurnal)tidal constituents are estimated based on the modified precise point positioning(PPP)algorithm in the static mode.We then carry out the inter-comparison of the OTL displacements between the GPS estimates and modeled values derived from seven global ocean tidal models and four earth models.The study shows that:1)The results from GPS agree best with TPXO7.2 model;the RMS misfit of M₂,N₂,O₁and Q₁are within 0.5 mm and 0.7 mm in the horizontal and vertical directions,respectively.2)Differences between different earth models exist mainly in M₂and N₂tidal constituents.3)The residual vectors of OTL displacements estimated between GPS estimates and the model correction values at most sites present spatial consistency in both the amplitude and direction,and residual anomalies are observed at a few sites,which probably can be attributed to the deviation of the priori SNREI earth model.