1
John Stuart Bladen, Alan Patrick Anderson: Position location system. British Telecommunications public company, Nixon & Vanderhye P C, June 22, 1999: US05913820 (380 worldwide citation)

Methods and apparatus are provided for locating the position, preferably in three dimensions, of a sensor by generating magnetic fields which are detected at the sensor. The magnetic fields are generated from a plurality of locations and, in one embodiment of the invention, enable both the orientati ...


2
J Michael Watters, Leo Strawczynski, David G Steer: Combining GPS with TOA/TDOA of cellular signals to locate terminal. Nortel Networks Corporation, Foley & Lardner, November 9, 1999: US05982324 (336 worldwide citation)

Aspects of global positioning system (GPS) technology and cellular technology are combined in order to provide an effective and efficient position location system. In a first aspect of the invention, a cellular network is utilized to collect differential GPS error correction data, which is forwarded ...


3
Alan C Heller, Brian M Evins, Robert G Karp: Method and apparatus for locating personnel and objects in response to telephone inquiries. Precision Tracking FM, Pravel Hewitt Kimball & Krieger, August 20, 1996: US05548637 (326 worldwide citation)

An automated position location system is provided which, in response to a telephone caller's inquiry and without human intervention, connects the caller directly to the telephone extension located nearest the individual or object of interest. A transmitter is attached to each individual (or object) ...


4
David I Dunthorn: Diffusion-assisted position location particularly for visual pen detection. Luedeka Neely & Graham, May 31, 1994: US05317140 (250 worldwide citation)

Systems and methods for optically determining the direction of an object, such as a pointer, relative to an imaging system, particularly systems where triangulation is employed to determine the location of a pointer within a generally planar viewing field, such as a touch screen. Rather than employi ...


5
Hobart R Everett Jr, Gary A Gilbreath, Rebecca S Inderieden, Theresa T Tran, John M Holland: Optically based position location system for an autonomous guided vehicle. The United States of America represented by the Secretary of the Navy, Harvey Fendelman, Peter A Lipovsky, Michael A Kagan, September 22, 1998: US05812267 (155 worldwide citation)

An optically based position location system, comprises multiple reflectors ositioned at known locations in an environment; a vehicle for traveling along a path in the environment; a first sensor for generating and detecting a collimated and polarized first light signal reflected from one of the refl ...


6
Norman Krasner: Calibration and correction system for satellite position location systems. Qualcomm Incorporated, Philip Wadsworth, Charles Brown, Richard Bachand, November 9, 2004: US06816111 (143 worldwide citation)

To provide accurate and quick position measurements in a practical mobile position location system, the GPS receiver is calibrated, a frequency error in the next time period is predicted using a first frequency locked to an externally transmitted signal, and a second frequency is generated by a GPS ...


7
David J Conroy, Mark Flowers: Surface position location system and method. Explore Technologies, Allston L Jones, November 11, 1997: US05686705 (131 worldwide citation)

Electrographic sensor and method for position determination of a selected position thereon. Sensor includes a conductive material layer having electrical resistivity and a surface, at least three spaced apart contact points electrically interconnected with the layer, a processor connected to the con ...


8
J Michael Watters, Leo Strawczynski, David G Steer: GPS and cellular system interworking. Nortel Networks, Foley & Lardner, June 19, 2001: US06249245 (125 worldwide citation)

Aspects of global positioning system (GPS) technology and cellular technology are combined in order to provide an effective and efficient position location system. In a first aspect of the invention, a cellular network is utilized to collect differential GPS error correction data, which is forwarded ...


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Steen A Parl, Julian Bussgang, Jay Weitzen, James M Zagami: Position location system and method. Signatron Technology Corporation, Hamilton Brook Smith & Reynolds P C, March 16, 1999: US05883598 (110 worldwide citation)

A position location system includes multiple base stations spaced over a region. A portable unit within the region transmits a locating signal which is received by the base stations. The base stations report amplitude, phase and time data related to the locating signal to a control station. The cont ...