Patent ID: 7756639

Claim:
A method of augmenting a navigation solution of a navigation system for a platform, comprising: within the navigation system, cyclically propagating a previous state for the platform into a current state for the platform over successive cycles, wherein the previous state includes any one or more of a previous position and a previous heading for the platform, and the current state includes any one or more of an initial position and an initial heading for the platform, and wherein at each cycle the resulting initial position and the initial heading become the previous position and the previous heading for a subsequent cycle; wherein cyclically propagating within the navigation system includes: processing satellite signals or dead-reckoning sensor signals to determine the current state from the previous state; matching any one or more of the initial position and the initial heading from the current state to predetermined map data to determine any one or more of a map-matching feedback position and a map-matching feedback heading; determining a relative accuracy between any one or more of the initial position and the initial heading and any one or more of the map-matching feedback position and the map-matching feedback heading; and if the relative accuracy is within a limit, overwriting any one or more of the initial position and the initial heading with any one or more of the map-matching feedback position and the map-matching feedback heading based upon the relative accuracy to update the current state.