A vehicle satellite navigation system is provided for generating a standard height for a geographic location where the vehicle is located. The system may include a satellite receiver (100) that is capable of generating position data as a function of signals received from navigation satellites. The position data may include a longitude, a latitude, and a ellipsoidal height. The system may store undulation values for a geographic area in an undulation grid model (146) or in a digital map. The system may determine an approximate undulation value for the position, and calculate the standard height value for the position.