TIMOTHY PRATT
Pilots at Catawba Rd, Blacksburg, VA

6621565, Sep 16, 2003

Sep 10, 2001

09/950144

Timothy Pratt - Blacksburg VA
Scott C. Casteel - Fairfax VA
Thomas M. Hedges - Great Falls VA
Donald Todd - Leesburg VA

Arc Second Inc. - Dulles VA

G01B 1126

3561414, 3561411

An optical transmitter for use in position location or position measurement systems includes (i) an assembly including two optical sources that generate two optical beams which diverge in known ways in a first and second plane, respectively, and are narrow in the orthogonal planes, (ii) a power source which provides power to the assembly to rotate it at a constant angular velocity or with a previously known pattern of velocities through each complete rotation of the assembly, and (iii) a signaling unit that emits a synchronization signal at a specific rotational position of the assembly. The optical transmitter can be used in systems for determining points, lines, planes, distances, areas, volumes, azimuth, elevation, range, angles, or any other positional or spatial variable. The optical transmitter has wide application in, for example, surveying, construction, and the creation of virtual or real environments.

6618133, Sep 9, 2003

Jul 26, 2002

10/205956

Thomas M. Hedges - Great Falls VA
Scott Casteel - Fairfax VA
Thomas Cuff - Frederick MD
Timothy Pratt - Blacksburg VA
Rick Slater - Reston VA
Donald Todd - Lottsburg VA

Arc Second, Inc. - Dulles VA

G01B 1126

3561414, 356 408, 3561415

An improved, low-cost optical transmitter and method useful in a three-dimensional measurement system wherein a plurality of operational parameters of said transmitter are calibrated during manufacture/assembly process to generate unique calibration data for each optical transmitter including data defining angles of each transmitters first and second radiant fan beams and the angle between the beams when the transmitter is leveled for operation in the system and wherein a detector/receiver in the system distinguishes between radiant beams from a plurality of individual transmitters operable within a given measurement field as a function of the selectively alterable rotational velocity calibration data for each of said transmitters and wherein said angular calibration data for each transmitter is operationally available to each detector/receiver operable in the system.

6535282, Mar 18, 2003

Oct 30, 2001

10/021402

Thomas M. Hedges - Great Falls VA
Hiro Takagi - Ashburn VA
Timothy Pratt - Blacksburg VA
Michael J. Sobel - Annandale VA

Arc Second, Inc. - Dulles VA

G01B 1126

3561413

An improved three-dimensional position detector and measurement system includes one or more transmitters that each transmit planar light beams and a strobe pulse and a receiver that responds to illumination from the beams and the strobe. The receiver in the system includes calibration logic for executing a quadratic mathematical algorithm to uniquely characterize said planar beams of each of said optical transmitters active in said measurement field. In one embodiment, the quadratic mathematical algorithm uses cones to represent the scan path of the planar beams.

6519029, Feb 11, 2003

Mar 21, 2000

09/532100

Thomas M. Hedges - Great Falls VA
Scott Casteel - Fairfax VA
Thomas Cuff - Frederick MD
Timothy Pratt - Blacksburg VA
Rick Slater - Reston VA
Donald Todd - Lottsburg VA

Arc Second, Inc. - Dulles VA

G01B 1126

3561414, 356 408, 3561415

An improved, low-cost optical transmitter and method useful in a three-dimensional measurement system wherein a plurality of operational parameters of said transmitter are calibrated during manufacture/assembly process to generate unique calibration data for each optical transmitter including data defining angles of each transmitters first and second radiant fan beams and the angle between the beams when the transmitter is leveled for operation in the system and wherein a detector/receiver in the system distinguishes between radiant beams from a plurality of individual transmitters operable within a given measurement field as a function of the selectively alterable rotational velocity calibration data for each of said transmitters and wherein said angular calibration data for each transmitter is operationally available to each detector/receiver operable in the system.

6545751, Apr 8, 2003

Feb 26, 2001

09/791736

Sean Beliveau - Leesburg VA
Edward R. Barrientos - Great Falls VA
Yvan Beliveau - Blacksburg VA
Thomas M. Hedges - Great Falls VA
Eric J. Lundberg - Reston VA
Edmund S. Pendleton - Arlington VA
Timothy Pratt - Blacksburg VA
Rick Slater - Reston VA
Michael J. Sobel - Annandale VA

Arc Second, Inc. - Dulles VA

G01B 1126

3561414, 356 408

An improved low cost theodolite position measurement system and process which is particularly useful in enabling a single operator to conveniently set up the system and calculate elevation (el) and azimuth (az) angle data. Only a single optical transmitter is positioned within a predetermined workspace thus significantly decreasing equipment costs and setup time. The single transmitter is positioned and leveled at a predetermined point in the workspace. In operation the single rotatably mounted transmitter head illuminates the workspace volume with a pair of spaced apart precalibrated fan beams which sweep the space and a periodically emitted reference strobe pulse. At least one optical receiver is selectively positionable within said workspace so that during each revolution of said single transmitter head said receiver receives a first position strike and a second position strike of said fan beams. To determine elevation angle data, tracker logic means responsive to said receiver determines a first tie interval separation between receiving said first position strike and said second position strike and calculation means for converting said first time separation interval into an elevation angle data. To determine an azimuth angle data said receiver receives a strobe pulse and a fan beam position strike, both of which are repeatedly transmitted with a known periodicity, determining a measure of time separation related to the strobe pulse and the position strike, and converting the measure of time separation into the azimuth angle data utilizing the known periodicity.

5100229, Mar 31, 1992

Aug 17, 1990

7/570268

Eric Lundberg - Blacksburg VA
Yvan Beliveau - Blacksburg VA
Timothy Pratt - Blacksburg VA

Spatial Positioning Systems, Inc. - Blacksburg VA

G01C 103, G01C 300, G01C 500

356 1

A spatial positioning apparatus providing three-dimensional position information and methods to utilize the position information for improved surveying, construction layout, equipment operations, manufacturing control and autonomous vehicle control is disclosed. The spatial positioning apparatus includes at least three, preferably four, fixed referent stations. A minimum of two, preferably three, of the fixed stations sweeps a spread laser beam horizontally across the site of interest. The remaining fixed station sweeps a spread beam vertically across the site of interest. A strobe signal is emitted from each fixed station when the rotation mechanism actuates a rotation datum. The spatial positioning apparatus also includes one or more portable position sensors. The portable position sensor includes a light sensitive detector, a computer, and a display. The x, y, z coordinates of the portable position sensor are obtained through a triangulation technique based on time marks received from each spread laser beam from the fixed stations and the rotation datum received from the strobe of each fixed station.

5461473, Oct 24, 1995

Sep 20, 1993

8/123891

Timothy Pratt - Blacksburg VA
Andrew W. Dornbusch - Blacksburg VA
Yvan J. Beliveau - Blacksburg VA
Eric J. Lundberg - Blacksburg VA
Michael H. Sweeney - Commerce Township MI

Spatial Positioning Systems, Inc. - VA

G01B 1126, H01J 4014, G02B 302

3561413

Improved transmitter and receiver units for use in spatial measurement system that are easy and inexpensive to manufacture while providing a high degree of reliability are disclosed. Specifically, the laser transmitter includes a laser emitter, a bearing/motor assembly coupled to the laser emitter, the bearing/motor assembly including a rotatable hollow spindle shaft through which a laser beam generated by the laser emitter passes and a motor for driving the spindle shaft, a prism assembly coupled to the spindle shaft, wherein the prism assembly divides the laser beam generated by the laser emitter into a pair of fanned laser beams, and reflecting means for reflecting the fanned laser beams generated by the prism assembly as counter-rotating fanned laser beams. The receiver unit preferably includes at least one optical receiver coupled to an extension member, a processing unit coupled to the optical receiver, and a receiver interface coupled to the processing unit.

5110202, May 5, 1992

Dec 31, 1990

7/636459

Andrew W. Dornbusch - Blacksburg VA
Yvan J. Beliveau - Blacksburg VA
Eric J. Lundberg - Blacksburg VA
Timothy Pratt - Blacksburg VA

Spatial Positioning Systems, Inc. - Blacksburg VA

G01C 103, G01C 300, G01C 500

356 1

A spatial positioning and measurement system provides three-dimensional position and/or measurement information of an object using one or more fixed referent station systems, and one or more portable position sensor systems. Each fixed station produces at least one primary laser beam which is rotated at a constant angular velocity about a vertical axis. The primary laser beam has a predetermined angle of divergence or angle of spread which is inclined at a predetermined angle from the vertical axis. Each fixed station also preferably includes at least one reflective surface for generating a secondary laser beam. The portable position sensor includes a light sensitive detector, computer, and a display. The light sensitive detector can be formed of at least one "axicon" which directs incoming light to a photosensitive detector. The photosensitive detector generates an electrical pulse when struck by crossing laser beam and sends this pulse to the computer.

5579102, Nov 26, 1996

Oct 5, 1995

8/539379

Timothy Pratt - Blacksburg VA
Andrew W. Dornbusch - Blacksburg VA
Yvan J. Beliveau - Blacksburg VA
Eric J. Lundberg - Blacksburg VA
Michael H. Sweeney - Commerce Township MI

Spatial Positioning Systems, Inc. - Blacksburg VA

G01C 300, G01B 1126, E02F 376, G02B 302

356 312

Improved transmitter and receiver units for use in spatial measurement system that are easy and inexpensive to manufacture while providing a high degree of reliability are disclosed. Specifically, the laser transmitter includes a laser emitter, a bearing/motor assembly coupled to the laser emitter, the bearing/motor assembly including a rotatable hollow spindle shaft through which a laser beam generated by the laser emitter passes and a motor for driving the spindle shaft, a prism assembly coupled to the spindle shaft, wherein the prism assembly divides the laser beam generated by the laser emitter into a pair of fanned laser beams, and reflecting means for reflecting the fanned laser beams generated by the prism assembly as counter-rotating fanned laser beams. The receiver unit preferably includes at least one optical receiver coupled to an extension member, a processing unit coupled to the optical receiver, and a receiver interface coupled to the processing unit.

5294970, Mar 15, 1994

Sep 6, 1991

7/755780

Andrew W. Dornbusch - Blacksburg VA
Eric J. Lundberg - Blacksburg VA
Yvan J. Beliveau - Blacksburg VA
Timothy Pratt - Blacksburg VA

Spatial Positioning Systems, Inc. - Blacksburg VA

G01B 1126, G01C 300

356152

A spatial positioning system includes fixed referent stations which emit rotating, divergent laser beams and a portable reflector. Each fixed station also includes a detector and a processor. The portable reflector may include retroreflectors or transponders. When the rotation of the laser beam is such that it is in line with a portable reflector, the transmitted laser beam is reflected off the portable reflector and received at the fixed receiver. For any point which is crossed by the fanned laser beams of a fixed station, a horizontal angle can be determined. Once these horizontal angles are known for three fixed stations, the point of intersection of three planes, and thus the three-dimensional position of the point, is determined.