Patent ID: 6073077
Filing Date: 2000-06-06
Classification: G01C,G01V

Abstract:
A method for determining gravity in an inertial navigation system, the inertial navigation system periodically producing and storing in memory position coordinates, the method comprising the steps:(a) retrieving the most recently determined position coordinates;(b) determining coordinates L.sub.u, L.sub.n, H.sub.u, and H.sub.n from the position coordinates, L.sub.u and L.sub.n being predetermined functions of geodetic latitude and H.sub.u and H.sub.n being predetermined functions of geodetic altitude;(c) determining the vertical component of gravity by substituting either or both L.sub.u and H.sub.u in a first polynomial expression;(d) determining the north-south component of gravity by substituting either or both L.sub.n and H.sub.n in a second polynomial expression;(e) utilizing the components of gravity determined in steps (c) and (d) in the next determination of the position coordinates.