The Global Positioning System Versus Gravity Disturbance Modeling in an Inertial Navigation System

摘要

The Global Positioning System provides a real-time means of updating an aircraft inertial navigation system to reduce position and velocity errors due, in part, to an inexact knowledge of the gravity field in which the aircraft is flying. Gravity disturbance modeling via such techniques as point mass or finite element modeling provides a real-time means of reducing this gravity field error. This paper demonstrates that should the navigator be denied the GPS signal, the modeling of gravity disturbances can adequately minimize the navigation error. In the presence of the GPS signal, the gravity disturbance component information, combined with GPS data via Kalman filtering, constitutes a further refinement in the system.