Study on mitigating the systematic errors between the announced orthometric heights in different years by corrector surface models

摘要

In Taiwan, the relative accuracies between benchmarks decreased due to the significant surface displacement with time and earthquake caused by the frequency activity of the crustal plate. Therefore, the Ministry of the Interior in Taiwan has re-surveyed the first-class benchmarks on the regular basis, and announced the orthometric heights of the benchmarks in different years, i.e. 2002, 2003, 2009 and 2015 respectively. To mitigate the systematic errors between orthometric heights obtained in different time and then facilitate the implementation of GNSS leveling, various corrector surfaces model are proposed in this paper. According to the preliminary test results, they show that after applying the optimal corrector surface models on corresponding cites, the accuracies of the difference of orthometric heights in each city are significantly improved, which is helpful for improving the accuracy of GNSS leveling.