Passively measured NEO bearings are used to augment an existing navigation system on-board the platform to correct the position estimate generated by the navigation system. The technology provides only a position correction based on passive NEO sightings but is applicable to a wide variety of platforms with different maneuvering profiles and update requirements. The technology directly calculates a position error based on the current position estimate and the passively measured and estimated bearings to three or more NEOs and provides the position error to the navigation system as a correction to the position estimate. The estimated bearings are computed from the current position estimate and the known orbits of the NEOs. The position error may be calculated from a single observation of multiple NEOs, allowing for frequent updates as needed and placing no restriction on platform maneuverability.