Applicability Analysis of Normal Height System in Taiwan Area
Other Title
正常高系統於臺灣地區之可應用性研究
Journal
Journal of the Chinese Institute of Civil and Hydraulic Engineering
Journal Volume
31
Journal Issue
6
Pages
535-543
Date Issued
2019
Author(s)
Abstract
A height reference system plays an important role in national developments as well as in scientific research. The orthometric height system is adopted as the current national height datum in Taiwan. Due to the non-parallelity of the leveling of the orthometric height system, the results of the height difference measured between the two observation points on different levels will be different. Besides, maintaining a nationalwide orthometric height system which is costly and timeconsuming. This study aims to build the normal heights datum by quasi-geoid. Normal height system is constructed by using three methods in this study, and the applicability in Taiwan is analyzed. Numerical results illustrate that the relative differences to the current orthometric height system are ±15 mm /√k, ±4 mm /√k, and ±13 mm /√k for the mathematical approach, gravity observation approach, and improved global spherical harmonic model approach, respectively. According to the research results, the gravity observation method can achieve the best accuracy, it is also the most expensive than other methods. Considering both the achievable quality and maintenance cost, the improved of the global spherical harmonic model approach fulfils the needs of most engineering applications, but with less cost than that of the traditional approach for maintaining the normal height system.
Type
journal article