Arcsecond, Inc.

Edmund S Pendleton

Thomas M Hedges

Eric J Lundberg

Michael J Sobel

Sean M Beliveau

Edward R Barrientos

Timothy Pratt

Andrew W Dornbusch

Yvan J Beliveau

Scott C Casteel

Rick Slater

Frey Wain

Doug Gaff

Roger Wells

Jeffrey F Skolnick

A method and system allows conversion of three-dimensional data from a default coordinate frame to an arbitrary user-selected coordinate frame. The method includes obtaining position data in a default coordinate frame and transforming the data into an alternate coordinate frame defined by the user. The alternate coordinate frame can be defined by allowing the user to select a plane, an origin, and an axis, using any desired coordinate system and in any desired orientation. The transformed data allows presentation of position measurements in a form that is relevant to the user's specific application.

Method and system for creating a user-selectable arbitrary coordinate frame

Positions can be precisely and accurately fixed instantaneously within a three-dimensional workspace. A system of two or more transmitters each continuously sweep the workspace with two fanned laser beams which are preferably about 90 degrees apart on the rotational axis of the transmitter. A receiving instrument includes, preferably, two light detectors which detect the time at which each fanned laser beam is incident thereon. The light detectors also detect a synchronization pulse from each transmitter that is emitted once per revolution. Beams from different transmitters are differentiated by different rotational speeds and, therefore, different beam incidence cycles. Because three intersecting planes uniquely define a point in three-dimensional space, by detecting at least three of the fan beams from the transmitters, the receiving instrument can calculate its position in the workspace. A Quick Calc setup procedure allows the use to define a desired coordinate system within the workspace.

Method and optical receiver with easy setup means for use in position measurement systems

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.

Low cost 2D position measurement system and method

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Arlington, VA, United States of America

Edmund S Pendleton