Estimates of ocean tide loading displacements and its impact on position time series in Hong Kong using a dense continuous GPS network
Estimates of ocean tide loading displacements and its impact on position time series in Hong Kong using a dense continuous GPS network
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DOI：
10.1007/s00190-009-0319-0
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发表时间：
2009-05
影响因子：
4.4
通讯作者：
Linguo Yuan;X. Ding;P. Zhong;Wu Chen;Ding-fa Huang
中科院分区：
文献类型：
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作者：
Linguo Yuan;X. Ding;P. Zhong;Wu Chen;Ding-fa Huang
利用全球定位系统（GPS） 3-7年的连续观测资料，估算了香港12个地点的8个昼夜和半日分量的三维海潮载荷位移。每天使用精确点定位（PPP）技术估计OTL位移，然后进行组合。将GPS获得的OTL位移与最近七个全球海潮模型的预测结果进行了比较。研究了OTL位移对GPS位置时间序列的影响。研究表明，gps反演的OTL位移（不包括K1和K2成分）与GOT4.7和NAO99b模型预测的结果最吻合。除了误差较大的S2、K1和K2分量外，GPS/模型的一致性一般在亚毫米级。在消除GPS与模型值之间的系统偏差后，M2、S2、N2、O1、P1和Q1的所有站点在水平和垂直分量上的误差分别小于0.5和1.0 mm，而K1和K2的误差较大（在2.5 mm以内）。整数模糊修正略微改善了OTL位移估计的东分量。研究还发现，除了K1和K2外，gps衍生的OTL校正可以用于日常数据处理，而不是模型预测。包括K2校正在内，位置时间序列的长期垂直速率可达1 mm/年，这需要进一步的研究来证实。
Three-dimensional ocean tide loading (OTL) displacements of eight diurnal and semidiurnal constituents at 12 sites in Hong Kong were estimated using 3–7 years of continuous global positioning system (GPS) observations. OTL displacements were estimated using the precise point positioning (PPP) technique on a daily basis and then combined. The OTL displacements obtained by GPS were compared with predictions using seven recent global ocean tide models. The effect of OTL displacements on GPS position time series was also investigated. The study shows that the GPS-derived OTL displacements (excluding K1 and K2 constituents) agree best with those predicted by the GOT4.7 and NAO99b models. The GPS/model agreement is generally at the sub-millimeter level, except for S2, K1, and K2 constituents with relatively large errors. After systematic biases between the GPS and model values are removed, the misfits of all sites for M2, S2, N2, O1, P1, and Q1 are less than 0.5 and 1.0 mm in the horizontal and vertical components, respectively, while larger misfits (within 2.5 mm) are observed for K1 and K2. Integer ambiguity fixing slightly improves the east component of OTL displacement estimates. The study also finds that GPS-derived OTL corrections, instead of model predicts, can be used in daily data processing with the exception of K1 and K2. Including K2 corrections, a secular vertical rate of up to 1 mm/year in position time series can be induced, which needs to be confirmed by further studies.