Differential Global Positioning system (DGPS) is an observation technique that can be used to reduce the ionosphere effects arising in ordinary GNSS. DGPS technique is used to increase the GNSS accuracy by reducing error associated with pseudo range but does not remove orbital ionosphere and troposphere errors. This paper investigates an integrated system for improvement the accuracy of differential GNSS and Real Time Kinematic (RTK) using Egyptian network as a case study. Three steps were used to reduce these errors. The comparison between DGPS observations and the treated observations used in determining the Egyptian network coordinate are presented. The resulting coordinate and of analysis of integrated system and computer programs are presented. The integration of use of precise ephemeris from International GPS Services (IGS) Network, Klobucher ionosphere model with Hopfield or Saastimoinen troposphere model improve the accuracy of DGPS to large extent.
Keywords: DGPS, Hopfield, Klobucher model, RTK, Saastimoinen and IGS