Supporting surveying projects and gravity aided navigation research.


geoids and anomalies

The gravitational field of the earth is non-uniform. The geoid is the shape the ocean surface would take if only gravity and the rotation of the Earth were considered. The geoid is the surface that defines zero elevation.

The geoid height is the difference between an ideal reference ellipsoid and the geoid. Variations in the geoid height are related to the density of the earth, so they can help us to better understand its internal structure. It is also used to measure surface elevations to high accuracy which is useful in applications such as GPS and surveying.

The gravity anomaly is the difference between the acceleration due to gravity on the Earth's surface and the value calculated assuming the reference ellipsoid.

connect your software to the EGM2008

The official 2008 Earth Gravitational Model EGM2008 was developed and released to the public by the National Geospatial-Intelligence Agency (NGA). This gravitational model is complete to spherical harmonic degree and order 2159.

Our EGM2008 API provides on-demand access to the EGM2008 model.

Geoid undulation values calculated using the API agree with corresponding values generated by the official EGM2008 harmonic synthesis program to within 1 mm.

We offer a 14 day free trial with ongoing subscriptions starting from $100 per month and supported by a Service Level Agreement.

geoid height calculator

Calculate the geoid height for your latitude and longitude.