Editing Geographic coordinate conversion (section)

=== Molodensky transformation ===

The Molodensky transformation converts directly between geodetic coordinate systems of different datums without the intermediate step of converting to geocentric coordinates (ECEF).<ref name=esri_eq_based>{{cite web|title=ArcGIS Help 10.1: Equation-based methods|url=http://resources.arcgis.com/en/help/main/10.1/index.html#//003r00000012000000|publisher=ESRI|access-date=5 March 2014|archive-date=4 December 2019|archive-url=https://web.archive.org/web/20191204151744/http://resources.arcgis.com/en/help/main/10.1/index.html#//003r00000012000000|url-status=live}}</ref>  It requires the three shifts between the datum centers and the differences between the reference ellipsoid semi-major axes and flattening parameters.

The Molodensky transform is used by the [[National Geospatial-Intelligence Agency]] (NGA) in their standard TR8350.2 and the NGA supported GEOTRANS program.<ref name=NGA_Datum>{{cite web|title=Datum Transformations|url=http://earth-info.nga.mil/GandG/coordsys/datums/index.html|publisher=National Geospatial-Intelligence Agency|access-date=5 March 2014|archive-date=9 October 2014|archive-url=https://web.archive.org/web/20141009125117/http://earth-info.nga.mil/GandG/coordsys/datums/index.html|url-status=live}}</ref> The Molodensky method was popular before the advent of modern computers and the method is part of many geodetic programs.