04209787 is referenced by 133 patents and cites 1 patents.

A method for monitoring the location of monitored objects within a monitored area wherein signpost units are positioned at the intersections of first and second coordinate grid lines and each signpost unit transmits a signpost code comprising a first portion corresponding to the first coordinate grid line and a second portion corresponding to the second coordinate grid line. The first coordinate grid lines are assigned numbers sequentially increasing in a first direction and the second coordinate grid lines are assigned numbers sequentially increasing in a second direction. The signpost unit output signals encoded with the signpost codes are received via vehicle units located in the monitored objects and the unique signpost codes are utilized to determine the location of the monitored object relative to one of the signpost units including the direction of the monitored object from the signpost unit.

Title
Method for monitoring the location of monitored objects
Application Number
568671
Publication Number
4209787
Application Date
August 31, 1978
Publication Date
June 24, 1980
Inventor
Charles C Freeny Jr
Ft. Worth
TX, US
Agent
Russell E Baumann
Charles E Snee III
Charles A Codding
Assignee
Gould
IL, US
IPC
G01S 3/02
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