10. Model of elevation conversion between tide systems in the area of Vietnam and its vicinity

Abstract

Currently, national elevation systems are often built with geoid or quasigeoid models as the elevation starting surface. In which, most of the gravity potential models are provided in the form of the bridge harmonic coefficients in the tidal-independent system. At the same time, the elevations of landmarks in the State elevation network used in the mean tidal system pass through the origin of Hon Dau. In the problem of building a geoid/quasigeoid model using global gravity potential models combining GNSS and leveling data, it is necessary to convert the above data sources into a unified tidal system. Research and build a model of elevation conversion in the form of a 1' × 1' grid grid bounded by the area from 0 to 30 degrees North latitude, from 95 to 125 degrees East longitude between 3 tidal systems: Mean tidal system (Mean Tide System), Zero Tide System, and Free Tide System in Vietnam's territorial waters and waters and its vicinity.