Improvement of Local Geoid Model in Thailand Using Least Square Collocation for Topographic Height Determination

Authors

  • Khetsophon Phinyo Department of Civil Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai, Thailand
  • Puttipol Dumrongchai Department of Civil Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai, Thailand

Keywords:

Geoid, Least Squares Collocation, EGM2008, THAI17G, Leveling

Abstract

Inconsistency between THAI17G and Ko Lak 1915 deteriorates the accuracy of height determination using THAI17G and GNSS survey. This research therefore aimed to improve a local geoid model in Thailand by using least-squares collocation. The model was computed by integrating the local gravimetric geoid model, THAI17G, and GNSS/leveling co-points of the Royal Thai Survey Department, which refers to the Ko Lak national vertical datum. Four hundred co-points were divided into 300 points to calculate conversion or correction surface between THAI17G and Ko Lak vertical datum and 100 points for geoid accuracy testing. The improved geoid model was obtained by adding the conversion surface to THAI17G and then compared with the geoid model using the polynomial equation method and EGM2008. The results showed that the geoid model obtained via the least-squares collocation method can best improve the geoid heights' accuracy. The model exhibits a standard deviation of ± 4.2 cm, representing 33 percent improved accuracy.

References

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Published

2021-09-30

How to Cite

Phinyo, K., & Dumrongchai, P. (2021). Improvement of Local Geoid Model in Thailand Using Least Square Collocation for Topographic Height Determination. Science and Engineering Connect, 44(3), 469–484. retrieved from https://ph04.tci-thaijo.org/index.php/SEC/article/view/10443

Issue

Vol. 44 No. 3 (2021): July - September

Section

Research Article

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