06028550 is referenced by 135 patents and cites 1 patents.

A system and method for determining which of a plurality of travel paths is taken by vehicles through area in which the performance of an automatic vehicle location (AVL) system is reduced. In one embodiment, the present invention divides a geographic region into a plurality of signature zones which are further divided into a plurality of signature zone cells. The signature zone cells in each signature zone correspond to travel paths that pass through an area having structures that prevent reception of GPS signals or any area where GPS alone is not sufficient to discern travel path. The present automatic vehicle path determination system then calculates correlation values for positions in each signature zone cell that correspond to the travel paths that pass through the signature zone. The position of each vehicles is monitored by an automatic vehicle location (AVL) system. The present automatic vehicle path determination system then determines the path taken by each vehicle passing through the signature zone. The present invention then communicates to the CAD system the path taken by each vehicle. Thus, the present invention provides a system which automatically determines which path is taken by a vehicle entering an area having structures that prevent reception of GPS signals, a system which can function in conjunction with an existing AVL or CAD system, and a system which reduces CAD system operator decision making processes.

Title
Vehicle guidance system using signature zones to detect travel path
Application Number
8/907763
Publication Number
6028550
Application Date
August 8, 1997
Publication Date
February 22, 2000
Inventor
James Sotelo
Scotts Valley
CA, US
Scott R Smith
Cupertino
CA, US
Peter L Froeberg
Cupertino
CA, US
Agent
Wagner Murabito & Hao
Assignee
Trimble Navigation
CA, US
IPC
G01S 5/02
H04B 7/185
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