Gravimetric Geoid Modeling for East Malaysia using the LSMSA Method

In contemporary geodetic studies, various techniques are employed to determine geoid heights. While the method of Remove-Compute-Restore (RCR) has been extensively utilized in the modelling of geoid heights, particularly in East Malaysia, where it was successfully developed in 2003 by the Department of Survey and Mapping Malaysia (DSMM), the Least Squares Modification of Stokes formula with Additive Corrections (LSMSA) stands as an alternative method for geoid development. Despite its contemporary relevance, the effectiveness of the LSMSA in developing geoid models over this region has yet to be explored. This research aims to analyze the effectiveness of the LSMSA method. A gravimetric geoid has been computed using a combination of terrestrial gravity, airborne gravity, and marine gravity data. Before developing the geoid model using the LSMSA method, all gravity data have been integrated and gridded using the 3D-LSC method. In order to analyse the performance of the derived gravimetric geoid model, a comparison with existing DSMM geoid model has been performed, and both have been evaluated against 23 GNSS leveling points. The findings suggest that the precision of the geoid model established in this investigation is marginally inferior when compared to the DSMM model, with accuracies of 0.09 m and 0.091 m, respectively. This outcome is expected, given that both models are derived from different data inputs, and it is anticipated that using identical data in geoid computation could potentially yield more favorable results.