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A Single-Pixel Touchless Laser Tracker Probe



Josh Gordon, David R. Novotny, Alexandra Curtin


We have developed a laser tracker probe, the Pixel Probe, that does not require physically contacting the object one is measuring and which has 3D spatial resolution of about 25 μm (in x,y,z) in the current configuration. This touchless laser tracker probe uses three machine vision cameras to discretize a scene down to the spatial resolution of a pixel. A single pixel from each camera field of view is linked to a laser tracker through a calibration process. The three pixels define a point in space that is used as a virtual touch probe where one places these pixels on an object by means of viewing the camera images. This allows one to measure with a laser tracker the location of small features (tens of μm ) on an object without needing physical contact. Given that the design of this system is easily scalable to higher resolution cameras and lenses, it is envision that this system could provide better than the current 25 μm resolution. The Pixel Probe excels at measuring objects that may prove difficult for existing laser tracker probes such as sharp edges and corners, amorphous, soft, and intangible objects. In addition one can register to the laser tracker features that appear in the images, and or geometries that are derived using machine vision edge and feature recognition algorithms. With the Pixel Probe it is also envision that other physical quantities based on optical imaging can be linked to a laser tracker such as thermal infrared data, spectral and polarimetric data. We present the concept, design, function, calibration, and operation of this system, as well as measurements using this system.
Conference Dates
July 20-23, 2015
Conference Location
Hollywood , FL, US
Conference Title
2015 Coordinate Metrology Society Conference


Laser Tracker, Spatial Metrology, Machine Vision, Alignment, Surveying, Manufacturing, Instrumentation, Optics


Gordon, J. , Novotny, D. and Curtin, A. (2015), A Single-Pixel Touchless Laser Tracker Probe, 2015 Coordinate Metrology Society Conference , Hollywood , FL, US, [online], (Accessed June 21, 2024)


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Created October 15, 2015, Updated October 6, 2023