Robert W Holden

US Patent:

6377208, Apr 23, 2002

Filed:

Feb 21, 1997

Appl. No.:

08/803937

Inventors:

Donald C. D. Chang - Thousand Oaks CA
Kar W. Yung - Torrance CA
Robert R. Holden - Santa Monica CA

Assignee:

Hughes Electronics Corporation - El Segundo CA

International Classification:

G01S 504

US Classification:

34235701

Abstract:

A method and system for determining a position of an object utilizes two-way ranging and polystatic techniques. A first communication transceiver at a first known location provides a bidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the first communication transceiver in response to the first ranging signal. The first communication transceiver further provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A second communication transceiver at a second known location provides a second unidirectional communication path between the second communication transceiver and the object wherein the second communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A signal processor determines a first path length corresponding to a first time length of the bidirectional communication path, a second path length corresponding to a second time length of the first and second unidirectional communication paths, and the position of the object based on the first and second known locations and the first and second path lengths.

US Patent:

6563457, May 13, 2003

Filed:

Nov 14, 2001

Appl. No.:

10/001501

Inventors:

Donald C. D. Chang - Thousand Oaks CA
Kar W. Yung - Torrance CA
Robert R. Holden - Santa Monica CA

Assignee:

Hughes Electronics Corporation - El Segundo CA

International Classification:

G01S 124

US Classification:

34235701, 342353, 342387

Abstract:

A method and system for determining a position of an object utilizes two-way ranging and polystatic techniques. A first communication transceiver at a first known location provides a bidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the first communication transceiver in response to the first ranging signal. The first communication transceiver further provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A second communication transceiver at a second known location provides a second unidirectional communication path between the second communication transceiver and the object wherein the second communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object. A signal processor determines a first path length corresponding to a first time length of the bidirectional communication path, a second path length corresponding to a second time length of the first and second unidirectional communication paths, and the position of the object based on the first and second known locations and the first and second path lengths.