Walter C Melton

US Patent:

6570534, May 27, 2003

Filed:

Feb 5, 2002

Appl. No.:

10/062555

Inventors:

Clark Cohen - Washington DC
David Lawrence - Mountain View CA
Stewart Cobb - Palo Alto CA
Paul Montgomery - Menlo Park CA
Miro Samek - Palo Alto CA
Kurt Zimmerman - Mountain View CA
Michael OConnor - Redwood City CA
Walter Melton - Columbia MO
Gregory Gutt - Lexington Park MD

Assignee:

IntegriNautics Corp. - Menlo Park CA

International Classification:

G01S 514

US Classification:

34235712

Abstract:

A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L1 and L2 bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L1 and L2 components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L1 carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L1 and L2 signals from the GPS signals in view. A digital signal processing component coupled to this sampling component processes the raw samples in synchronous, batch form including a step to precisely unwrap the P(Y) carrier phase to baseband.

US Patent:

6762714, Jul 13, 2004

Filed:

Apr 3, 2003

Appl. No.:

10/405702

Inventors:

Clark Cohen - Washington DC 20003
David Lawrence - Mountain View CA 94043
Stewart Cobb - Palo Alto CA 94303
Paul Montgomery - Menlo Park CA 94025
Miro Samek - Palo Alto CA 94306
Kurt Zimmerman - Mountain View CA 94040
Michael OConnor - Redwood City CA 94061
Walter Melton - Columbia MO 65203
Gregory Gutt - Lexington Park MD 20653

International Classification:

G01S 514

US Classification:

34235712, 375325

Abstract:

A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L and L bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L and L components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L and L signals from the GPS signals in view. A digital signal processing component coupled to this sampling component processes the raw samples in synchronous, batch form including a step to precisely unwrap the P(Y) carrier phase to baseband.

US Patent:

6882314, Apr 19, 2005

Filed:

Jul 30, 2002

Appl. No.:

10/209782

Inventors:

Kurt R. Zimmerman - Mountain View CA, US
Clark E. Cohen - Washington DC, US
David G. Lawrence - Mountain View CA, US
Walter C. Melton - Columbia MO, US
Henry Stewart Cobb - Mountain View CA, US
Paul Yalden Montgomery - Menlo Park CA, US

Assignee:

Novariant, Inc. - Menlo Park CA

International Classification:

G01S003/02
G01S001/08

US Classification:

342464, 342386

Abstract:

Apparatus and methods for resolving integer ambiguities in position determination. An embodiment of the invention includes a reference system, augmented with multi-frequency pseudolites using a carrier phase differential GPS implementation, and a mobile system. In one embodiment, the components of the reference system includes one or more multi-frequency pseudolites, one or more multi-frequency reference receivers, a data link standing alone or built into the pseudolites, and the associated antennae for each of these elements. The components of the reference system may be stationary. The mobile system may include a multi-frequency receiver and its associated antennae. Because the mobile systems may passively receive information, an unlimited number of mobile systems may be included in any given embodiment of the invention. A multi-frequency pseudolite uses a single frequency source to synthesize all of the multiple carrier frequencies and all of the multiple base band signals modulated onto carrier frequencies for transmission.

US Patent:

7023381, Apr 4, 2006

Filed:

Mar 17, 2003

Appl. No.:

10/391161

Inventors:

Kurt R. Zimmerman - Mountain View CA, US
Clark E. Cohen - Palo Alto CA, US
David G. Lawrence - Mountain View CA, US
Walter C. Melton - Los Altos CA, US
Henry Stewart Cobb - Mountain View CA, US
Paul Yalden Montgomery - Menlo Park CA, US

Assignee:

Novariant, Inc. - Menlo Park CA

International Classification:

G01S 1/08
G01S 3/02

US Classification:

342386, 342464

Abstract:

Apparatus and methods for resolving integer ambiguities in position determination. An embodiment of the invention includes a reference system, augmented with multi-frequency pseudolites using a carrier phase differential GPS implementation, and a mobile system. In one embodiment, the components of the reference system includes one or more multi-frequency pseudolites, one or more multi-frequency reference receivers, a data link standing alone or built into the pseudolites, and the associated antennae for each of these elements. The components of the reference system may be stationary. The mobile system may include a multi-frequency receiver and its associated antennae. Because the mobile systems may passively receive information, an unlimited number of mobile systems may be included in any given embodiment of the invention. A multi-frequency pseudolite uses a single frequency source to synthesize all of the multiple carrier frequencies and all of the multiple base band signals modulated onto carrier frequencies for transmission.

US Patent:

55771220, Nov 19, 1996

Filed:

Dec 29, 1994

Appl. No.:

8/367440

Inventors:

John F. Schipper - Palo Alto CA
Walter C. Melton - Los Gatos CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

H04K 100
H09B 7185
G01C 2100

US Classification:

380 28

Abstract:

Methods for secure communication of location and other information by two spaced apart receivers in a location determination (LD) system, such as GPS, GLONASS and LORAN-C, that use pseudorange corrections to enhance the accuracy of the computed present location of an LD receiver. A pseudorange correction signal PRC(t;i;j), presenting a correction of a pseudorange measurement made at time t at an LD receiver number i from an LD signal issued by an LD signal source number j, is transmitted at a consecutive sequence of times t=t. sub. 0, t. sub. 1, t. sub. 2,. . . , t. sub. n. The pseudorange correction signal PRC(t. sub. n ;i;j), or a message sent in a time interval t. sub. n-1