New additional Global Geopotential Models [GGMs] have now been released into the public domain, those including data from the CHAMP, GREACE and GOCE dedicated satellite gravimetric mission. Those satellite tracking data have resolved the long wave length component of the global gravity field with rather very high accuracy [10].Therefore, it is important to evaluate those new models over Egypt to determine which; of them is the most appropriate GGM there. In this study a comparison of the performance of three of the GGMs released between 1996 tell now (EGM96, EGM2008 and EIGEN-6C 2011) over Egypt is made. The gravity anomalies computed from the models are compared with point free air gravity anomalies on land. The results have indicated the outstanding performance of EGM2008 to the other examined GGMs undoubtedly. EGM2008 has1.23 times better statistics than the EGM96 and 2.54 times than EIGEN-6C 2011, in terms of root mean square error [r.m.s.e]. |
