# Common Ellipsoid Parameters

Ellipsoid
Parameters
Ellipsoid
Name
"165" ANS CLARKE 1858 GRS80 WGS84 WGS72 International
1924
Major Semi
Axis
a 6378165.000 6378160.000 6378293.645 6378137 6378137 6378135 6378388
Inverse
Flattening
1/f 298.3 298.25 294.26 298.2572221 298.2572236 298.26 297
Flattening f = 1 / f 0.003352330 0.003352892 0.003398355 0.003352811 0.003352811 0.003352779 0.003367003
Minor Semi
Axis
b = a * ( 1 - f ) 6356783.287 6356774.719 6356617.938 6356752.314 6356752.314 6356750.520 6356911.946
Eccentricity e 0.081813334017 0.081820179996 0.082372092204 0.081819191043 0.081819190843 0.081818810663 0.081991889979
Eccentricity
squared
e**2=2f-f**2=(a**2-b**2)/a**2 0.006693421623 0.006694541855 0.006785161574 0.006694380023 0.006694379990 0.006694317778 0.006722670022
Second
Eccentricity
e' 0.082088521821 0.082095437120 0.082652976376 0.082094438152 0.082094437950 0.082094053920 0.082268889607
Second
Eccentricity
squared
e'**2=e**2/(1-e**2)=(a**2-b**2)/b**2 0.006738525415 0.006739660796 0.006831514504 0.006739496775 0.006739496742 0.006739433689 0.006768170197