UNCLASSIFIED

Reference Ellipsoid Parameters

Reference Ellipsoid

ID
Code

Semi-Major
Axis a

Semi-Minor
Axis b

Inverse
Flattening f

Airy (1930)

AA

6377563.396000000

6356256.909237285

299.3249646000000

Australian National

AN

6378160.000000000

6356774.719195306

298.2500000000000

Bessel 1841

 

 

 

 

Ethiopia, Indonesia, Japan, Korea

BR

6377397.155000000

6356078.962818188

299.1528128000000

Namibia

BN

6377483.865000000

6356165.382966325

299.1528128000000

Clarke 1866

CC

6378206.400000000

6356583.800000000

294.9786982139058

Clarke 1880

CD

6378249.145000000

6356514.869549776

293.4650000000000

Everest

 

 

 

 

Brunei & E. Malaysia (Sabah & Sarawak)

EB

6377298.556000000

6356097.550300897

300.8017000000000

India 1830

EA

6377276.345000000

6356075.413140240

300.8017000000000

India 1956*

EC

6377301.243000000

6356100.228368101

300.8017000000000

Pakistan*

EF

6377309.613000000

6356108.570542461

300.8017000000000

W. Malaysia and Singapore 1948

EE

6377304.063000000

6356103.038993154

300.8017000000000

W. Malaysia 1969*

ED

6377295.664000000

6356094.667915204

300.8017000000000

Geodetic Reference System 1980 (GRS 80)

RF

6378137.000000000

6356752.314140356

298.2572221010000

Helmert 1906

HE

6378200.000000000

6356818.169627891

298.3000000000000

Hough 1960

HO

6378270.000000000

6356794.343434343

297.0000000000000

Indonesian 1974

ID

6378160.000000000

6356774.504085540

298.2470000000000

International 1924

IN

6378388.000000000

6356911.946127946

297.0000000000000

Krassovsky 1940

KA

6378245.000000000

6356863.018773047

298.3000000000000

Modified Airy

AM

6377340.189000000

6356034.447938534

299.3249646000000

Modified Fischer 1960 (South Asia)

FA

6378155.000000000

6356773.320482736

298.3000000000000

South American 1969

SA

6378160.000000000

6356774.719195306

298.2500000000000

World Geodetic System 1972 (WGS 72)

WD

6378135.000000000

6356750.520016093

298.2600000000000

World Geodetic System 1984 (WGS 84)

WE

6378137.000000000

6356752.314245179

298.2572235630000

NOTE: Semi-major and semi-minor axis values are in meters, while inverse flattening values are unitless. Values that end in multiple zeroes are defined (or measured) values, while other values are derived through calculation. With the exception of the CC ellipsoid, semi-minor axis values are calculated from the semi-major axis and inverse flattening values.

* Through adoption of a new yard to meter conversion factor in the referenced country.

UNCLASSIFIED