Estimation of Uncertainty in Three Dimensional Coordinate Measurement by Comparison with Calibrated Points

This paper details a method of estimating the uncertainty of dimensional measurement for a three dimensional coordinate measurement machine. An experimental procedure was developed to compare three dimensional coordinate measurements with calibrated reference points. The reference standard used to calibrate these reference points was a fringe counting interferometer with a multilateration like technique employed to establish three dimensional coordinates. This is an extension of the established technique of comparing measured lengths with calibrated lengths. Specifically a distributed coordinate measurement device was tested which consisted of a network of Rotary-Laser Automatic Theodolites (R-LATs), this system is known commercially as indoor GPS (iGPS). The method was found to be practical and was used to estimate that the uncertainty of measurement for the basic iGPS system is approximately 1 mm at a 95% confidence level.


J E Muelaner, Z Wang, O Martin, J Jamshidi, P G Maropoulos

Department of Mechanical Engineering, The University of Bath, Bath, UK

Published in

Measurement Science and Technology, 2010

Accepted for Publication on 16/12/09

Volume and page number information

21 () 025106


Results given in this paper were obtained using the original Workspace software
and a typical 4 transmitter setup. Further testing has shown that uncertainty may
be reduced by using newer software versions, and more complicated configurations
with more hardware.




Official URL:


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1 thought on “Estimation of Uncertainty in Three Dimensional Coordinate Measurement by Comparison with Calibrated Points”

  1. Hi,

    I am trying to calculate the uncertainty in an analytical method and need some help. I was wondering would you be interested in helping me?

    Thank you,
    Anup Thakur, PhD (Chemistry)

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