Geoid Modelling in the Sultanate of Oman

This thesis covers the process taken to complete the Oman National Geoid Model 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 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 which was used to calculate the gravimetric geoid using the remove-compute-restore method. The remove step was completed using the residual terrain model modelling technique to calculate the quasigeoid. The gravimetric geoid was computed by adding the N- 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 with a standard deviation of 30 cm.