The role of dead reckoning and inertial sensors in future general aviation navigation

Possible configurations for a general aviation autonomous navigation system are studied. Doubtless, an advanced GPS receiver is a "must have" system component. GPS has had some outages due to unintentional interference or even intentional jamming and aircraft should be able to navigate through such an event. Natural candidates for GPS backup are inertial sensors, magnetic compass, and air-speed sensors. All these sensors can be calibrated during GPS availability. Moreover, for dead reckoning systems, wind velocity can be estimated as well. This paper presents an original statistical model for wind variations that matches actual data very well. Using this model and a parametric family of inertial measurement sensors, horizontal position errors during a GPS outage are compared for a variety of configurations: a dead reckoning system, stand alone inertial sensors and inertial sensors integrated with the dead reckoning system.