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Geodetic Reference System 1980 (GRS80)

adopted by the International Association of Geodesy (IAG) during the General Assembly 1979. Principal parameters are:

parameter symbol alue
defining constants    
equatorial radius of the Earth a 6378137 m
geocentric gravitational constant    
(including the atmosphere) GM 3986005 · 108 m3s-2
dynamical form factor    
(excluding permanent tides) J2 108263 · 10-8
angular velocity of the Earth w 7292115 · 10-11 rad s-1
derived geometrical parameters    
semiminor axis (polar radius) b 6356752.3141 m
first excentricity e2 0.00669438002290
flattening f 1 : 298.257222101
mean radius R1 6371008.7714 m
radius of sphere with same surface R2 6371007.1810 m
radius of sphere with same volume R3 6371000.7900 m
derived physical parameters    
normal potential at ellipsoid U0 62636860.850 m2s-2
Normal gravity at equator ge 9.7803267715 m s-2
Normal gravity at pole gp 9.8321863685 m s-2

Last Update: 07.12.2007 08:26