Abstract:

The article presents the detailed mathematical formulas to calculate the geoid height and gravity anomaly by using spherical harmonic coefficients and established a computer program ״Geomat2015״ by Matlab programming language. The geoid heights and gravity anomalies have been calculated by using spherical harmonic coefficients of the Earth Gravitational Model EGM2008 in Gulf of Tonkin-Vietnam is represented in the form of grid squares of size (6 ' x 6 ') with 874 points grid. The results are compared with the results provided by The International Centre for Global Earth Models (ICGEM) shows the correctness of calculation results with statistics: The maximum, minimum deviation and standard deviation of the geoid heights being 0.0082m; -0.0030m and ± 0.0015m respectively and gravity anomalies being 0.0588mgal; -0.2607 mgal and ±0.0264mgal respectively.