Gravimetry
A medium approximation of the acceleration due to gravity g in Germany is often set to 9.81 m/s2 which varies with ± 0.004 m/s2 in the North and the South. A lot of applications in physics and technique, which underlie the gravity influence, expect an uncertainty below. The following small program allows to calculate the local gravity depending on the latitude and the height above sea level with a global relative uncertainty of Δg/g ~10-4. The implemented algorithm is based upon the mathematical model of the so-called Normal Gravity Field. The longitude is not required, since the model is defined by a rotationally symmetric ellipsoid.(Geodetic Reference System 1980):
with
: Latitude
Hp : Height above sea level
A comparison of calculated and locally measured gravity values can be seen in a tabulated sample of 
50 European cities or in the associated 
map of gravity anomalies.
Eine web-fähige Einbindung eines globalen Höhenmodells ist für einen späteren Zeitpunkt vorgesehen.