Michael R Allison

US Patent:

61989894, Mar 6, 2001

Filed:

May 21, 1999

Appl. No.:

9/315801

Inventors:

Boris G. Tankhilevich - Walnut Creek CA
Michael Timo Allison - Santa Clara CA

Assignee:

Trimble Navigation LTD - Sunnyvale CA

International Classification:

G06F 1700
G06F 700

US Classification:

701 2

Abstract:

A method and a system for remote control of a rover over a long base line is disclosed. The system includes a primary base station (PBS), a secondary base station (SBS), a rover, a primary long line data link between PBS and SBS, and a secondary two-way data link between the SBS and the rover. The primary data link and the secondary data link comprise a long baseline feedback loop that is used to transmit the control data to the rover, to adjust the control data, and to transmit back from the rover to the SBS and to the PBS the collected feedback data.

US Patent:

57576467, May 26, 1998

Filed:

Nov 7, 1996

Appl. No.:

8/745579

Inventors:

Nicholas Charles Talbot - Cupertino CA
Michael Timo Allison - Santa Clara CA
Mark Edward Nichols - Sunnyvale CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

G01S 302
G01S 502
G06F16500

US Classification:

3644499

Abstract:

A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e. g. , once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e. g. , ten times a second, and used to propagate solutions between epochs.

US Patent:

56106149, Mar 11, 1997

Filed:

Sep 13, 1995

Appl. No.:

8/528506

Inventors:

Nicholas C. Talbot - Cupertino CA
Michael T. Allison - Santa Clara CA
Peter Griffioen - Clayton, AU

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

H04B 7185
G01S 502
G01C 2100
H04B 1700

US Classification:

342352

Abstract:

A real-time kinematic system includes base and rover GPS units connected by a data link. The rover unit is typically moved to points of interest during a survey while the base remains over a fixed, and known location. An initialization testing program of the present invention is mounted on a personal computer platform that forces in the rover a loss of signal tracking, thus simulating losses in signal reception caused by obstructions of the satellite signals. A complete initialization is forced to occur. The test program uninitializes the RTK solution by causing a loss of integer ambiguities resolution by forcing a loss of lock on one or more satellites. The test program then monitors the subsequent initialization process, e. g. , the time needed to search for phase ambiguity candidates, discovering the prevalent satellite geometry, determination of whether the correct ambiguity candidate was found, finding the ratio of the second best to best solution variances of the ambiguity candidates in the list throughout the candidate propagation process or similar statistical test, computing the RMS error of the solution at the time that initialization was declared and after initialization, and calculating the baseline vector between the rover and base at the time of initialization and after initialization. All such statistical parameters are logged and used in post and real-time analyses of the initialization algorithm.

US Patent:

58410260, Nov 24, 1998

Filed:

May 15, 1996

Appl. No.:

8/647701

Inventors:

Geoffrey R. Kirk - San Francisco CA
Michael Timo Allison - Santa Clara CA
Ian Viney - St. Martins, NZ
Paul N. Skoog - Fremont CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

G01C 2100

US Classification:

73178R

Abstract:

A centimeter level survey system includes reference base station and rover GPS units connected by a radio data link. Each includes recorders for the storage of raw measurement information including range, phase, cycle counts and time information. The rover unit is typically moved to points of interest during a survey while the base remains over a fixed, and known location. Generally, the base antenna is located to optimize a clear view of the sky. The rover is subject to interruption of the radio data link from the primary reference station. During periods that the rover is initialized and in contact with the primary reference station base station over the radio data link, the rover provides real time centimeter level position solutions to a survey user, otherwise, the rover records its raw measurements in a file that begins with the last valid initialization information and that ends with any newly reestablished initialization information. A post-processor is initialized by transferring the position filter states and covariance matrix of the real-time processor in the rover directly to the position filter of the post-processor, provided that continuous satellite tracking and no carrier cycle slips have occurred.

US Patent:

58900918, Mar 30, 1999

Filed:

Feb 19, 1998

Appl. No.:

/027827

Inventors:

Nicholas Charles Talbot - Cupertino CA
Michael Timo Allison - Santa Clara CA
Mark Edward Nichols - Sunnyvale CA

Assignee:

Trimble Navigation Ltd. - Sunnyvale CA

International Classification:

G01S 302
G01S 502
G06F16500

US Classification:

701215

Abstract:

A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e. g. , once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e. g. , ten times a second, and used to propagate solutions between epochs.

US Patent:

59163003, Jun 29, 1999

Filed:

Jul 18, 1997

Appl. No.:

8/896929

Inventors:

Geoffrey R. Kirk - San Francisco CA
Michael Timo Allison - Santa Clara CA
Paul Skoog - Santa Rosa CA
Ian Timothy Viney - Christchurch, NZ

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

G06G 778

US Classification:

701213

Abstract:

A method and apparatus for automatic event detection and processing is provided. A positioning system receiver includes a position measurement device and a logging device. The position measurement device is configured to receive and process signals from a positioning system. The logging device is coupled to the position measurement device for recording data received from the position measurement device. The logging device records the data at a current logging rate. The positioning system receiver detects an event via an external sensor or with reference to satellite data, for example. In response to the event, the logging device automatically modifies data logging processing such as the current logging rate. Additionally, to allow a post processing system to go backwards in time relative to the event, the current logging rate may be increased for a predetermined amount of time preceding the occurrence of the event. According to another aspect of the invention, the data logging processing of a survey system, such as a real-time kinematic (RTK) system including a base reference station and a roving unit, may be altered based upon an event.

US Patent:

55196209, May 21, 1996

Filed:

Feb 18, 1994

Appl. No.:

8/199387

Inventors:

Nicholas C. Talbot - Cupertino CA
Michael T. Allison - Santa Clara CA
Mark E. Nichols - Sunnyvale CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

G01S 302
G01S 502
G06F16500

US Classification:

364449

Abstract:

A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e. g. , once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e. g. , ten times a second, and used to propagate solutions between epochs.

US Patent:

56027419, Feb 11, 1997

Filed:

May 10, 1996

Appl. No.:

8/644422

Inventors:

Nicholas C. Talbot - Cupertino CA
Michael T. Allison - Santa Clara CA
Mark E. Nichols - Sunnyvale CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

G01S 302
G01S 502
G06F16500

US Classification:

3644497

Abstract:

A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e. g. , once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e. g. , ten times a second, and used to propagate solutions between epochs.