Method of improving satellite reacquisition preformance for integrated GP/IG navigational systems

摘要

A method of reacquiring a satellite signal within an integrated GP/IG navigation system includes detecting a loss of synchronization between a timing code in the satellite signal and a corresponding reference timing code. The method includes receiving position data from an inertial guidance unit. The position data is representative of an estimated position (and its associated uncertainty) of the navigation system. The method also includes estimating a distance from the navigation system to the satellite, as a function of the position data, and deriving an initial delay from the distance. The method includes delaying the reference timing code, with respect to the timing code embedded in the satellite signal, by an offset delay substantially equal to the initial delay. The method includes incrementally varying the offset delay until the timing code embedded in the satellite signal is synchronized with the reference timing code, or until the offset delay equals a predetermined end limit value.