Evaluation of the EGM96 model of the geopotential in Peninsular Malaysia

• Main Authors: Wan Mohd. Akib, Wan Abdul Aziz, Fashir, Hassan, Zainon, Othman
• Format: Conference or Workshop Item
• Language: English
• Published: 1998
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.utm.my/id/eprint/11944/1/OthmanZainon_Evaluation_OfTheEgm96Model_.pdf; http://eprints.utm.my/id/eprint/11944/

A set of higher degree and order of spherical harmonic potential coefficients ( Cnm, Snm ) plays an important part in gravity field modelling , e.g. reference model for the gravimetric solution. The satellite and terrestrial data used in the development of the global geopotential model have improves with time. For example, the most recent EGM96 model incorporate new 30’ X 30’ surface gravity anomalies, normal equations from direct altimetry data (TOPEX/POSEIDON, GEOSAT & ERS-1). This paper presents the accuracy of the anomalous gravity field determined from the potential coefficients of the EGM96 model over the Malaysia region. Dividing the region into 0.5 x 0.5 block and testing the mean fit for each block, it shows how well the residual gravity anomalies is modelled by EGM96 model compared to geopotential model OSU91A. To assess the quality of the estimated geoid height from EGM96(NEGM) and OSU91A (NOSU) , comparison are made with the corresponding height derived from 136 GPS control poinst (NGPS/Lev). The overall results of absolute and relativen geoid height differences showed that the EGM96 is definitely the best high-order geopotential model to be used as reference gravity field modelling for the Peninsular Malaysia.