This thesis covers the process taken to complete the Oman National Geoid Model (ONGM) project for the Sultanate of Oman. The steps taken to repair poor quality and badly referenced gravity data are explained. Each observation point was assigned a new orthometric height, its position was updated to geodetic coordinates, and its “observed” gravity was inversely calculated. The major biases that existed in the ground dataset were fixed using airborne free air anomalies at altitude. The ground data was merged with downward continued airborne gravity and the merged dataset was used to calculate the gravimetric geoid using the remove-compute- restore (RCR) method. The remove step was completed using the residual terrain model modelling technique (RTM), a General Bathymetric Chart of the Oceans (GEBCO) model mixed with a 30” NASA Shuttle Radar Topography Mission (SRTM) digital terrain model (DTM), and an expansion of the EGM08 Global Geopotential Model (GGM) to degree and order 360. The “residual anomalies” were run through the Stokes integral with Wong Gore Tapering using the GRAVSOFT software package, the effects were restored to calculate the quasigeoid. The gravimetric geoid was computed by adding the ?−?separation term to the quasigeoid and was fitted to the GPS-on-benchmarks provided by Oman. The external accuracy of the computed gravimetric geoid is 14 cm below mean sea level (MSL) with a standard deviation of ±30cm.

This thesis covers the process taken to complete the Oman National Geoid Model (ONGM) project for the Sultanate of Oman. The steps taken to repair poor quality and badly referenced gravity data are explained. Each observation point was assigned a new orthometric height, its position was updated to g...