Skip to content
English
www.veexinc.com
  • There are no suggestions because the search field is empty.

What is the Ellipsoid (Elip.) Value in the GNSS Receiver Coordinates?

Earth is not actually round (spherical), so an ellipsoid is considered a simple geoid approximation and used as a reference model (datum) to calculate altitude, based on position. World Geodesic System 1984 (WGS84) is a better worldwide reference.

Earth is not perfectly round (spherical), so an ellipsoid is considered a simple geoid approximation that can be used as a reference model (datum) to account for spheroid distortions in the calculation of altitude (vertical height), based on position. The World Geodesic System 1984 (WGS84) is considered a better worldwide reference. The WGS84 mathematical ellipsoid has been used by GPS since January 1987.

  • Ellipsoid is a mathematical shape obtained by rotating an ellipse around its minor axis (a flattened sphere). It is commonly referred to as a spheroid.
  • Ellipsoid height, also referred as geodetic height, is the difference between the ellipsoid and a point on the Earth’s surface (not the same as altitude over the sea level).
  • Geoid height is the offset value between the reference geoid and the ellipsoid models.
  • Orthometric height or Altitude is the distance between a point on the Earth’s surface and the geoid. Since the geoid represents the Mean Sea Level, this is the value most antenna installers are interested about.

GPS/GNSS receivers use a smoothed model of sea level to calculate elevation. The model is called a reference ellipsoid. This means that the elevation reading from the GPS/GNSS receiver is not the vertical distance from true sea level, but rather the distance from the reference ellipsoid.