Based on the Earth Gravitational Model EGM2008 with 1minx1min resolution, this paper presents the fitness of the VN2000 datum oriented by using transformation parameters published by the MONRE. | Science & Technology Development, Vol 18, 2015 Prospecting fitness of VN2000 datum to EGM2008 Le Trung Chon HCMC University of Technology,VNU-HCM (Bài nhận ngày 22 tháng 04 năm 2015, nhận đăng ngày 05 tháng 6 năm 2015) ABSTRACT Based on the Earth Gravitational parameters are quite small, the author Model EGM2008 with 1minx1min resolution, suggest ignoring the influence of the three this paper presents the fitness of the rotation angles when positioning and VN2000 datum oriented by using transforming from VN2000 to WGS84. This transformation parameters published by the helps simplify processing of calculating MONRE. The results showed that VN2000 baselines measured by GPS technology from WGS84 to VN2000. datum is better than WGS84 datum in Vietnam territory. Because rotation Key words: EGM2008, VN2000 datum, WGS84, Geoid, Ellipsoid, GPS. INTRODUCTION h=H+ The shape of the earth is very complex. Geoid is defined as a physical equipotential surface that represents the shape of the Earth, which is also used to determine the surface elevation of a point in space. Distance according to the plumb line from one point to Geoid called orthometric height H. Since geoid surface is not mathematical surface, ellipsoid is used to determine the coordinates of point with latitude B, longitude L and geodetic height h. The distance between the geoid and ellipsoid known as Geoid height N, is expressed through the following equation: s X X Y Y z Z VN 2000 Z WGS 84 y On 27/2/2007, MONRE announced 7 parameters transformation of coordinates by decision 05/2007/QĐ-BTNMT [2] as following: ∆X = ; ∆Y = , Trang 82 (1) A reference system (geodetic datum) is based on conditions that match the following equation: 2 i (2) min Depending on the data i of the equation (2), i 1 global datum (as WGS84) or local datum (as VN2000) will be defined. The transformation of coordinates from a global .
