Abstract

Building a coordinate reference system suitable to the natural characteristics of each country is very important in the task of economic and social development and national security and defense. In July 2000, the VN-2000 National Coordinate Reference System was officially applied and replaced the HN-72 Coordinate Reference System. Regarding technical solutions, the VN-2000 coordinate system uses the WGS-84 reference system based on the principle of locating the WGS-84 ellipsoid closest to the local geoid surface in Vietnam. During over 20 years of development, the WGS-84 reference system has been updated through many versions, but the VN-2000 coordinate system is still in "static". Simultaneously, building new or updated VN-2000 coordinate reference systems according to versions of the WGS-84 reference system faces many difficulties because the WGS84 parameters and data weren't widely and fully published. Therefore, this article will propose a solution to upgrade the VN-2000 reference system from CORS stations connected to the global network IGS (International GNSS Service) and compare it with an update by the WGS-84 reference system