Jordan Transverse Mercator (JTM) (Arabic: نظام تربيع ميركاتور الأردني المستعرض) is a grid system created by the Royal Jordan Geographic Center (RJGC). This system is based on 6° belts with a Central Meridian of 37° East and a Scale Factor at Origin (mo) = 0.9998. The JTM is based on the Hayford ellipsoid adopted by the IUGG in 1924. No transformation parameters are presently offered by the government.[1] However, Prof. Stephen H. Savage of Arizona State University provides the following parameters for the projection:
Jordan Transverse Mercator Geographic Coordinate System: GCS_International_1924Datum: D:International_1924Spheroid: International_1924 Axis: 6378388 Flattening: 297Prime Meridian: Greenwich Prime Meridian Longitude: 0Units: Degree Unit Scale Factor: 0.017453292519943295
Projection: Transverse Mercator False Easting: 500,000 False Northing: -3,000,000 Central Meridian: 37 Scale Factor: 0.9998 Central Parallel: 0Units: Meter Scale Factor 1Three-parameter transformation to WGS84 is: ΔX = –86 meters ΔY = –98 meters ΔZ = –119 meters
Prof. Savage also offers software, ReprojectME!, which will convert coordinates between JTM and other systems. (See http://daahl.ucsd.edu/gaialab/# for more information.)
The central meridian of 37° East is roughly midway between the extremes of Jordan: the Karameh Border Crossing with Iraq is close to 39° East, while the city of Aqaba on the Red Sea is close to 35° East.