台灣地區GPS高程測量誤差改進之綜合探討

A Study on the Improvement of GPS Height System Surveying in Taiwan

陳清河(Ching-Ho Chen) ； 陳春盛(Chun-Sung Chen)

《地籍測量：中華民國地籍測量學會會刊》 16卷1期 (1997/03) Pp. 1-16

https://doi.org/10.29609/YYWYLL.199703.0001

摘要

本文旨在藉著各種測高方法模式之改良、及沿岸地區地層下陷之研究，以提昇測高之精度，進而獲得台灣地區高精度之高程系統，以提供台灣地區經濟建設所需之高精度高程。針對上述目標，本文包括下列幾項研究子題：（一）對流層模式改良及高精度GPS高程之研究。（二）構建與評估電離層遲延模式以增益GPS高程之精度。（三）建立臺灣地區數值密度模型以供重力地形改正之用。（四）調整GPS衛星軌道計算方式以提昇其精度。（五）沿岸地區地層下陷預警系統之先期研究。其中，子題（一）、（二）主要著眼於提昇GPS觀測量在測高方面之精度，亦即研究GPS訊號傳播過程中，受到對流層與電離層之遲延效應所造成的影響。並提供區域性（台灣地區）之適當模式，以增益GPS測得之橢球高的精度。子題（三）主要在於建立台灣地區數值密度模型(DDM, Digital Density Model)，將來配合台灣地區之數值地形模型(Dem, Digital Elevation Model)，以作為地形改正之用。子題（四）則是採用調整軌道與不調整軌道的方式來處理GPS觀測量資料，以計算分析基線之重複性的精度，並評估其對高程精度的影響。子題（五）應用前述四個子計畫之成果，選定了台灣西南沿海地區來進行沉陷變形之研究。

並列摘要

This paper aims to improve the models of the GPS heighting method and to study the stratigraphic subsidence of coastal area in Taiwan. Therefore, the precision of heights can be elevated. Besides, a higher precision height system in Taiwan area can be set up. Consequently, the precise heights can be offered for economic construction use in Taiwan.To focus on this object, the subprojects of this project include:1. A study on the refinement of troposphere model and high precision GPS heighting.2. Building and evaluation ionospheric delay model to improve accuracy of GPS heights.3. Establishment of Taiwan Digital Density Model.4. Improvement of orbit calculation for GPS in Taiwan region.5. Preliminary study on subsidence alarm system in coastal area.In the foregoing subprojects, the object of the subproject 1 and 2 is to promote the precision of GPS height. In other words, these two subprojects aim to study the influences from the tropospheric and ionospheric delay and to offer suitable models for raising the precision of GPS height in Tqiwan Area.In the subproject 3, we aim to offer the DEM and DDM models in Taiwan Area for terrain correction.In the subproject 4, we aim to improve the GPS height precision by adjusting the orbit calculation for both broadcast ephemeris and postcomputed ephemeris.In the subproject 5, a testing coastland in south-western Taiwan is chosen, the results of the subproject 1, 2, 3 and 4 are applied to study the subsidence of this testing area.