An inertial/gps navigation system

Abstract From the Canadian patent

A receiver that uses a single processor to control a GPS sub-system and an inertial ("INS") sub-system and, through software integration shares GPS and , INS position and covariance information between the sub-systems. The receiver time tags the INS measurement data using a counter that is slaved to GPS time and the receiver then uses separate INS and GPS filters to produce GPS and INS position information that is synchronized in time. The GPS/INS receiver utilizes GPS position and associated covariance information in the updating of an INS Kalman filter, which provides updated system error information that is used in propagating inertial position, velocity and attitude. Whenever the …