Location surveying for the main water supply units of Baghdad city using the Iraqi geodetic reference system

The hydraulic pressure head of the water supply network is represented by the elevation head for a specified reference. The Iraqi geodetic reference (also called local reference) which is established for Baghdad city, can be used to locate the water supply unit for this study. The Iraqi reference is represented by the difference between the surfaces of the ellipsoid and that of the geoid to re-position the ellipsoid surface in order to achieve the goal in minimizing the difference. Each country depends on its geodetic references based on a universal ellipsoid, and the experimental work of this research is to unify the geodetic system (WGS84/ITRF08) with the Iraqi geodetic reference of (ITRF08). This unification can be considered for the city of Baghdad/ Al-Adhamiya district for water supply networks, in order to obtain more accurate locations with selected points of these networks to produce precise maps for water pipes applications. The coordinates of these selected points have been measured using the DGPS static observing method with (WGS/ ITRF08) reference and (Iraqi/ ITRF08) reference to ensure the accuracy of the elevations extracted from these references. Due to the differences between the vertical datum of the elevations with the (WGGS84/ ITRF08) reference and (Iraqi/ ITRF08) reference for the same points, it is substantial to unify the vertical datum for all points. The observed elevation difference between these references is about 1.349m and this disparity can be unified with new coordinates according to the Iraqi geodetic reference of (ITRF08). These average differences are verified by observing two points (517301,511701) by GPS values for these points with Iraqi Geodetic reference.