臺灣海潮負載效應於測量改正計算之研究

The study of ocean tide loading corrections in Taiwan

臺灣海潮負載（OTL）效應之數值推估重力模式SGOTL（Hwang and Huang, 2012）、位移模式DISOTL（Hwang and Huang, 2013）已分別開發完成，並對外發表網頁，提供各界進行OTL效應改正線上計算服務，特別是對於海潮變化較大的近岸測站，利用該模式改正後之觀測成果，精度確實獲得改善。由於臺灣海峽週邊海潮效應明顯，分析馬祖GPS站之徑向各分潮振幅合量最高可達5.5 cm；新竹超導重力站之各分潮振幅合量約有11 μgal，對於高精度測量產生不小影響，有改正必要。本文除發表內政部公告219個一等衛星控制點（GPS連續觀測站）之OTL計算服務外，也進行OTL對於精密單點定位（Precise point positioning, PPP）技術計算成果影響與改正之研究。 A numerical model to compute SGOTL (gravity) (Hwang and Huang, 2012) and DISOTL (displacement) (Hwang and Huang, 2013) resulting from ocean tide loading (OTL) had been successfully developed, and online computation service was released, especially for coastal stations with large ocean tides. By use of this mode, the accuracy of observation is indeed improved. Around the Taiwan Strait, OTL-induced vertical displacement of Matsu GPS station can be up to 5.5 cm, and the gravity of Hsinchu superconducting gravity Station is about 11 μgal, where such large OTL effects will have a profound influence on the precise measurements. Ministry of the Interior (MOI) announces a new set of geodetic datum and TWD97 coordinates at 2010. In the study, online service of OTL computation at 219 first-order GPS continuous stations has been released and the accuracy of precise point positioning (PPP) derived coordinates affected and modeled by OTL were analyzed.

A numerical model to compute SGOTL (gravity) (Hwang and Huang, 2012) and DISOTL (displacement) (Hwang and Huang, 2013) resulting from ocean tide loading (OTL) had been successfully developed, and online computation service was released, especially for coastal stations with large ocean tides. By use of this mode, the accuracy of observation is indeed improved. Around the Taiwan Strait, OTL-induced vertical displacement of Matsu GPS station can be up to 5.5 cm, and the gravity of Hsinchu superconducting gravity Station is about 11 μgal, where such large OTL effects will have a profound influence on the precise measurements. Ministry of the Interior (MOI) announces a new set of geodetic datum and TWD97 coordinates at 2010. In the study, online service of OTL computation at 219 first-order GPS continuous stations has been released and the accuracy of precise point positioning (PPP) derived coordinates affected and modeled by OTL were analyzed.