Towards a real time leveling using the VRS GPS network in Jeddah

Jeddah Municipality (JM) established a Virtual Reference Stations (VRS) GPS network for different survey applications. JM provides the users with VRS service to enable them to reach a real time cm-accuracy of horizontal position with single GPS receiver.To achieve high accuracy for GPS leveling applications a precise geoid model must be defined and applied with the GPS measurements. One of the methods that are used for developing a local geoid model is enhancing a Global Geopotential Model (GGM) with a comprehensive set of gravity, GPS, and leveling measurements.This paper evaluates six of the recent GGMs with measured GPS and leveling data in Jeddah to select the best model to be used with VRS GPS. That model will be the first candidate to develop a local geoid model for Jeddah. The results indicate that the GO-CONS-GCF-2-TIM-R1 model is the best available model which gives the minimum standard deviation of geoidal height difference.