The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2003
Filed:
May. 15, 2001
Mark Barton, Schaumburg, IL (US);
Navigation Technologies Corp., Chicago, IL (US);
Abstract
A method implemented on a navigation system in a vehicle for determining the position of the vehicle relative to a road network. The navigation system uses a geographic database that contains data that represent positions of roads upon which the vehicle travels. Using the output from a GPS system, and optionally outputs from other sensors, the navigation system matches the positions of the vehicle to the locations of the roads represented by the data contained in the geographic database. Upon detecting an event from which the position of the vehicle with respect to the roads represented by the data contained in the geographic database can be determined with a relatively high degree of accuracy, a correction factor is determined. The correction factor is an offset (i.e., a distance and direction) of the GPS position reported during the event to the known-to-be-highly-accurate position. The correction factor is then used to adjust subsequently obtained GPS readings for a limited period of time, i.e., while the same atmospheric conditions apply. This period of time may be 10-20 minutes.