Patent ID: 7299056

Claim:
A method for determining a location of a vehicle, the method comprising: establishing a first zone in a work area, the first zone being where reception location data is applied exclusively as refined location data, a location determining receiver providing the reception location data from reception of electromagnetic energy transmitted from terrestrial or satellite beacons; establishing a second zone in the work area, the second zone being where optical location data is applied exclusively as refitted location data; determining at least one of reception location data and optical location data to estimate preliminary location data indicating whether the vehicle is located in the first zone or the second zone; and selecting one of the reception location data and the optical location data as the refined location data based on whether the preliminary indication data indicates that the vehicle falls within the established first zone or the second zone, respectively; where the optical location data is selected as the refined location data if the estimated preliminary data is inconclusive with respect to the first zone and second zone and if the reception location data falls below a threshold reliability level.