Abstract:

The paper deals with the basis of theory used for calculating height anomalies by using spherical harmonic coefficients and applies for computing the height anomalies in Vietnam territory. The height anomalies have been calculated by using fully-normalised spherical harmonic coefficients of the Earth Gravitational Model EGM2008 up to degree 2190 in Vietnam territory are evaluated by the results computed and provided by the US. National Geospatial-Intelligence Agency (NGA) which express a reasonable agreement with maximum deviation, minimum deviation and standard deviation being 0.0019m; -0.0010m and 0.0006m corresponding. For evaluating the agreement of the model EGM2008 in Vietnam the results were also compared with GPS-levelling derived height anomalies at 816 points with maximum discrepancy and minimum discrepancy being 1.613m and -0.170m corresponding, and standard deviation of 0.297m.