Estimation the components of deflection of the vertical for a point in Baghdad City - Iraq

Abstract

Abstract In the age of the satellite geodesy, the GNSS is widely used in development of geodetic networks and that give much application, for that reason the study is to estimate deflection of the vertical of a point in Baghdad City in Iraq, the estimated depends on the orthometric height, which computed through the levelling and the ellipsoidal height, which computed from the GPS observations. Due to the lack of survey data and the difficulty of taking terrestrial measurements as a result of the security situation the authors used only 5 points for the national network in Baghdad. The deflection of the vertical component component ξ in the north-south direction calculated as ξ=2.5”±0.001” and the prime vertical component η in the east-west direction calculated as η=5.23” ±1.5”. The results were obtained showing that it can calculate the deflection of the vertical at sufficient accuracy.