Patent ID: 6169497
Filing Date: 2001-01-02
Classification: G08G

Abstract:
A method of locating a target by triangulation in a region lacking a fixed positioning reference for participating in the triangulation wherein the target includes a transmission unit adapted to broadcast a radio signal in response to an initiation event, said method comprising the steps of: providing first and second mobile tracking stations that transit the region of the target; initiating a broadcast of a radio signal from said target in response to the occurrence of said initiation event; determining the direction of origin of said radio signal relative to said first station; substantially simultaneously with the determination of the direction of origin of said signal relative to said first station; a) determining the position of said first station at or above the surface of the earth; b) transmitting said position and said direction of origin from said first station to said second station; c) determining the position of said second station; d) determining the direction of origin of said signal at said second station; and subsequently triangulating said position of said target at said second station from said positions of said first and second stations and said directions of origin of said radio signal from said target to said first and second stations.