Detection of Systematic Error in Mean Dynamic Topography Model DTU10MDT on the Territorial Waters of Vietnam

Ha Minh Hoa

Vietnam Institute of Geodesy and Cartography (VIGAC), Vietnam

Abstract: In the sea bordering countries, a mean dynamic topography (MDT) model, that in Geodesy is called as mean sea surface topography model (MSST), is a very important source of data for creation of a different types of marine thematic maps and research on ocean dynamical processes. However, a majority of the permanent tide gauge stations with water level measurement period more 18.6 years are located at the some onshore islands. So the mean sea levels (MSL) determined at the onshore permanent tide gauge stations don’t permit to construct MSST covering the entire national waters. Over the past decade many international techno-scientific organizations had constructed a global highly accurate mean dynamic topography (MDT) models based on the global Earth’s Gravity models (EGM) and the MSS models determined from altimetric data and had supplied users with these models. These valuable models with the MSL determined at the onshore permanent tide gauge stations fully allow to construct the MSST model on the entire national waters.

The MSST model had been constructed based on the corresponding mean sea surface (MSS) model, whose accuracy depends on many factors, especially on an accuracy of the used global tide model. In practice, complicated hydro-meteorological conditions in shallow water area near the coast don’t permit to construct the highly accurate global tide model in the inshore shallow water regions. That may be a potential cause of presence of a systematic error in the MSST model.

This scientific article will present a research results for construction of the mean sea surface topography model MDTVN2015 on national waters of Vietnam based on the international DTU10MDT model created by the National Space Institute (NSI) belonged to the Technical University of Denmark (DTU). The main focus of this article is a detection of potential systematic error in the DTU10MDT model on national waters of Vietnam based on the national normal heights of the local mean sea surfaces at the onshore permanent tide gauge stations.

Key words: Mean Dynamic Topography (MDT), Mean Sea Surface Topography (MSST), Mean Sea Surface (MSS), systematic error, Mean Sea Level (MSL)