SPATIAL POSITION DETERMINATION SYSTEM

• US 20090021371A1
• Filed: 09/03/2008
• Published: 01/22/2009
• Est. Priority Date: 07/25/2001
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Inventors: Radin, Lon B.
• Granted Patent: US 7,928,841 B2
• Time in Patent Office: Days
• US Class Current: 340/539.130
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G08B 21/0244 System arrangements wherein the alarm criteria uses signal delay or phase shift

Abstract

A system is disclosed that determines a spatial position of a tracker device relative to an object sending a return signal to the tracker. Such a system advantageously maintains phase accuracy between a forward signal from the tracker device and the return signal from the object. The system can include, as part of a tracker device, a reference signal generator, a transmitter, a receiver, and a spatial position computer. The reference signal generator is responsive to and phase-stabilized by a broadcast signal, e.g., a signal received from a commercial AM broadcast transmitter. The transmitter and receiver are both coupled to and phase-stabilized by the tracker reference signal generator. Variations and methods with different advantageous features are also described.

Claims

1. A tracker system comprising:

a transmitter coupled to and phase-stabilized by a reference signal generator;

a receiver coupled to and phase-stabilized by the reference signal generator and responsive to a return signal from a transponder unit that is coupled via field radiation to the tracker system, which return signal is triggered by a signal from the transmitter;

a global positioning module to determine the location of the tracker system; and

a spatial position computer coupled to the receiver, the global positioning module and the transmitter, responsive to indicia of a phase relationship between an output signal from the transmitter and a return signal from the transponder and to the location of the tracker system determined by the global positioning module whereby the spatial position computer determines a spatial position of the transponder unit.