FIG Peer Review Journal


Simple Precise Coordinates Transformations for Geomatics Applications in Makkah Metropolitan Area, Saudi Arabia (4953)

Gomaa Dawod, Meraj Mirza and Khalid Al-Ghamdi (Saudi Arabia)
Dr. Gomaa Dawod
Umm Al-Qura University
P.O.Box 715
Saudi Arabia
Corresponding author Dr. Gomaa Dawod (email: dawod_gomaa[at], tel.: + 966 551402093)

[ abstract ] [ paper ] [ handouts ]

Published on the web 2011-03-16
Received 2010-11-22 / Accepted 2011-02-10
This paper is one of selection of papers published for the FIG Working Week 2011 in Marrakech, Morocco and has undergone the FIG Peer Review Process.

FIG Working Week 2011
ISBN 978-87-90907-92-1 ISSN 2307-4086


With the rapid growth of utilizing the Global Positioning System (GPS) technology in Saudi Arabia, the issue of transforming GPS-based coordinates to the local coordinates system becomes a crucial concern for geomatics applications. Traditional mathematical models for datum conversion (such as Molodensky-Badekas formula) require a comprehensive geodetic background and a specialized computer software. This paper aims to develop simple, still precise, coordinate transformation algorithms particularly for Geographic Information Systems (GIS) applications. A dataset of high-precision geodetic control points with known GPS and Saudi Geodetic Datum (SGD2000) coordinates, within the metropolitan area of Makkah city, has been compiled and utilized in data processing. Results of classical 7-parameters similarity transformation are presented. Additionally, four regression formulas have been developed to convert GPS coordinates (geographic and projected sets) to their local values just by using a calculator. Precision estimates of these regression equations have been anticipated to be within 0.3 meter. Compared with the accuracy of pre-defined transformation parameters utilized in commercial GIS software (which is about 10 meters), the obtained accuracy is quite reasonable for geomatics activities. The proposed approach is practical and decreases both cost and time of integrated GPS/GIS projects, as utility detection, mobile GIS, image georeferencing, and topographic mapping.
Keywords: Professional practice; GNSS/GPS; Positioning; Engineering survey; Reference systems; GPS; GIS; SGD2000; datum transformation; geomatics applications; Saudi Arabia