Historical Earth Ellipsoids
The following table lists 9 ellipsoids which (except Clarke's) were the best estimation of the Earth's figure when they were published:
| Name | Equatorial axis (m) | Polar axis (m) | Inverse flattening, |
|---|---|---|---|
| Delambre, France 1810 | 6,376,985.0 | 308.6465 | |
| Airy 1830 | 6,377,563.4 | 6,356,256.913224 | |
| Bessel 1841 | 6,377,397.155 | 6,356,078.963 | 299.1528128 |
| Clarke 1866 | 6,378,206.4 | 6,356,583.8 | 294.9786982 |
| Helmert 1906 | 6,378,200.0 | (close to WGS84!) | 298.30 |
| International 1924 | 6,378,388.0 | 6,356,911.9 | 297.0 |
| Krassowski 1940 | 6,378,245.00 | (for Eastern Europe) | 298.3 |
| Internat. 1967 Luzern | 6,378,165.00 | (incl. Sat.Geodesy) | 298.25 |
| GRS 80 | 6,378,137.00 | 6,356,752.31414 | 298.257222101 |
| WGS 1984 | 6,378,137.00 | 6,356,752.3142 | 298.257223563 |
Read more about this topic: Earth Ellipsoid
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