Converting Coordinates Between the Local Geodetic Reference and the Global Geodetic Reference for Selective Sites in Babil Province

A geodetic transformation is a mathematical operation that takes coordinates of a point in one coordinate system and returns the same coordinates in another coordinate system. This study aimed to show the compatibility between global positioning system coordinates and the local maps in Iraq; this compatibility will be made for locations in the Babil province. In the study area, fifteen control points have been chosen. GPS measures geographic and projected coordinates depending on the Universal Transverse Mercator projection and the World Geodetic System 1984 datum. In Iraq, the measured geographic coordinates are converted to projected coordinates using a geographic information system based on Clarke 1880 ellipsoid. To facilitate the conversion of the coordinates, both formulas and parameters are provided for any point in the study area between the two systems using a GPS receiver and the ArcGIS software. The present study shows that the differences in easting coordinates are about -287.630 m, while the differences in northing coordinates reach 278.525 m. It was concluded that the various datums might play a significant role in producing maps and updating those maps for engineering works.