Vertical_Datum_Code Vertical_Datum_Name Vertical_Datum_Abbreviation Area_of_Use Length_Unit_Code Length_Unit_Name Information_Source Remarks_ Revision_Date code name abbr - UNITS.code UNITS.name - - - 5001 Airy 1830 ellipsoid United Kingdom - Great Britain 9001 metre Original definition of a and b in feet. OSGB defines 1/f to 7 d.p. 02-Jun-95 5002 Airy Modified 1849 ellipsoid Ireland United Kingdom - Northern Ireland 9001 metre 02-Jun-95 5003 ANS ellipsoid Australia Papua New Guinea 9001 metre 02-Jun-95 5004 Bessel 1841 ellipsoid 9001 metre 02-Jun-95 5005 Bessel Modified ellipsoid Norway 9001 metre 02-Jun-95 5006 Bessel Namibia ellipsoid Namibia 9001 metre 02-Jun-95 5007 Clarke 1858 ellipsoid Trinidad and Tobago 9001 metre Clarke 1858/II solution. Derived parameters: a = 6378293.639m; 1/f = 294.26068 02-Jun-95 5008 Clarke 1866 ellipsoid Clarke 1866 9001 metre Uses Benoit 1896 foot-metre ratio. Derived parameter: 1/f = 294.97870 02-Jun-95 5013 Clarke 1880 (Arc) ellipsoid 9001 metre 02-Jun-95 5010 Clarke 1880 (Benoit) ellipsoid 9001 metre Uses Benoit 1896 inch-metre ratio. Derived parameter: 1/f = 293.46623 02-Jun-95 5011 Clarke 1880 (IGN) ellipsoid 9001 metre 02-Jun-95 5012 Clarke 1880 (RGS) ellipsoid 9001 metre 02-Jun-95 5014 Clarke 1880 (SGA 1922) ellipsoid 9001 metre Used in Old French Triangulation (ATF). 02-Jun-95 5015 Everest 1830 (1937 Adjustment) ellipsoid 9001 metre Used for the 1937 adjustment of Indian triangulation 02-Jun-95 5016 Everest 1830 (1967 Definition) ellipsoid Malaysia - East Malaysia 9001 metre Adopted 1967 for use in East Malaysia. Uses Sears 1928 inch-metre ratio. 02-Jun-95 5017 Everest 1830 (1975 Definition) ellipsoid 9001 metre Used by Surveys of India and Pakistan since 1975. Derived parameter: 1/f = 300.80174 02-Jun-95 5018 Everest 1830 Modified ellipsoid Malaysia - West Malaysia 9001 metre Adopted 1967 for use in West Malaysia. Uses Benoit 1898 inch-metre ratio. 02-Jun-95 5031 GEM 10C ellipsoid 9001 metre Used for GEM 10C Gravity Potential Model. 02-Jun-95 5019 GRS 1980 ellipsoid 9001 metre Adopted by IUGG 1979 Canberra. 02-Jun-95 5020 Helmert 1906 ellipsoid Egypt 9001 metre Helmert 1906/III solution. 02-Jun-95 5021 INS ellipsoid Indonesia 9001 metre 02-Jun-95 5022 International 1924 ellipsoid 9001 metre Adopted by IUGG 1924 in Madrid. Based on Hayford 1909/1910 figures. 02-Jun-95 5023 International 1967 ellipsoid 9001 metre Adopted by IUGG 1967 Lucerne. Inverse flattening defined to 2 d.p. 02-Jun-95 5024 Krassowsky 1940 ellipsoid China 9001 metre 02-Jun-95 5026 NWL 10D ellipsoid 9001 metre Used by Transit Broadcast Ephemeris before 1989. Also referred to as WGS72 spheroid. 02-Jun-95 5025 NWL 9D ellipsoid 9001 metre Used by Transit Precise Ephemeris between October 1971 and January 1987. 02-Jun-95 5032 OSU86F ellipsoid 9001 metre Used for OSU86 gravity potential (geoidal) model. 02-Jun-95 5033 OSU91A ellipsoid 9001 metre Used for OSU91 gravity potential (geoidal) model. 02-Jun-95 5027 Plessis 1817 ellipsoid 9001 metre 02-Jun-95 5028 Struve 1860 ellipsoid 9001 metre 02-Jun-95 5029 War Office ellipsoid 9001 metre 02-Jun-95 5030 WGS 84 ellipsoid 9001 metre 02-Jun-95 5035 02-Jun-95 5101 Newlyn United Kingdom - Great Britain 9001 metre 02-Jun-95 5102 North American Vertical Datum 1929 NAVD29 United States 9003 US survey foot 02-Jun-95 5103 North American Vertical Datum 1988 NAVD88 United States 9001 metre 02-Jun-95 5104 Yellow Sea 1956 Yellow Sea China 9001 metre 02-Jun-95 5105 Baltic Sea Baltic Armenia Azerbaijan Estonia Georgia Kazakhstan Latvia Lithuania Russia 9001 metre 02-Jun-95 5106 Caspian Sea Caspian Azerbaijan - offshore Kazakhstan - offshore Russia - Caspian Sea Turkmenistan - offshore 9001 metre 28.0 metres below Baltic Sea Datum 02-Jun-95 5107