Assessments of recent Global Geopotential Models based on GPS/levelling and gravity data along coastal zones of Egypt

Abstract The orthometric height has an essential role in a variety of civil engineering projects and it is defined as the length curved plumbline from point (on earth surface) to its intersection with geoid surface. Leveling process considered most accurate technique for obtaining these heights. However, regardless potentials, tedious, costly, time consuming. Recently many organizations research centers have developed multi Global Geopotential Models (GGMs) depending on several types available gravity datasets estimate heights GNSS measurements. In this study, we present evaluation assessment accuracy five recent popular GGM S : XGM2016, XGM2019e, EIGEN-6C4, GO_CONS_GCF_2_TIM_R6e, EGM2008 using actual 145 GNSS/leveling points 96 terrestrial points. goal find best fit model along study area located coastal zones Egypt distances about 1,970 km further determination modeling at regional scale. selection areas basically was due their developmental, urban, economical importance continuous need protection works fight against erosion caused by climate change global warming. results indicated that undulation, GO_CONS_GCF_2_TIM_R6e estimation Mediterranean Sea line, while XGM2019e_2159 suitable line Red Sea. And regarding anomalies, reliable GGMs are EIGEN-6C4 Bouguer free-air anomaly, respectively.