Method for determining vertical and horizontal GPS position using altitude information

摘要

A method of using altitude information to arrive at a more accurate GPS position. A 3D GPS position is used as an initial estimate. The latitude and longitude of the initial estimate are used to retrieve an altitude from a database. This altitude is used to calculate a 2D GPS position. The 2D GPS position is then used to retrieve another altitude from the database, and the calculate-retrieve process is continued until the calculation converges.