Refined geoid model for the United Arab Emirates

A precise gravimetric geoid plays a role of tremendous importance in successful military operations. This work is aimed to determine the precise gravimetric geoid of the United Arab Emirates (UAE). In doing so, the GRAVSOFT package is used in computing the 1-D and 2-D FFT gravimetric geoids for the UAE between 23o N to 27o N and 52o E to 56o E. The new precise geoid has been computed and determined based on the GRS80 reference ellipsoid. The geometric geoid (NGPS) at 157 GPS/Levelling stations has been used in evaluating the accuracy of the newly computed gravimetric geoid. Results show that GPS–derived ellipsoidal height of the selected GPS points with accuracy of ±3 cm. Further, the standard deviation of the difference between gravimetric geoid and geometric geoid indicates how well the fitting of the two surfaces. Meanwhile, the mean of the difference indicates how the two surfaces are vertically shifted with respect to the geometric geoids. In addition, the new gravimetric geoid heights that have been computed at 19 checking points (BMs) showing agreement with the corresponding geometric geoid heights at ±5cm level of accuracy. With additional gravity data over land and marine area of the UAE, the precision of the geoid would be improved for the future GPS/Levelling application