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Type-B uncertainty analysis of gravity-based determinations of triaxial-accelerometer properties by simulation of measurement errors



Jon Geist, Michael Gaitan


We simulate the effect of gimbal-alignment errors and rotational step-size errors on measurements of the sensitivity matrix and intrinsic properties of a triaxial accelerometer. We restrict the study to measurements carried out on a two-axis accelerometer-calibration system with a measurement and analysis protocol that we have described previously. As well as imperfections in the calibration system, we simulate imperfect orthogonality of the accelerometer axes and non-identical sensitivity of the individual accelerometers in an otherwise perfect triaxial accelerometer, but leave characterization of other accelerometer imperfections such as non-linearity for future study. Within this framework, sensitivity-matrix errors are caused by imperfections in the construction and installation of the accelerometer calibration system, but not by the accelerometer imperfections included in the simulations. We use the results of this study to assign Type-B uncertainties to the components of the sensitivity matrix and related intrinsic properties due to imperfections in the measurement system. For calibrations using a reasonably well manufactured and installed multi-axis rotation stage such as that simulated in this paper, we estimate upper bounds to the relative standard uncertainties of the order of 1×10−5, 2×10−5, 5×10−5, and 2×10−4 for the intrinsic sensitivities, diagonal elements of the sensitivity matrix, off-diagonal elements of the sensitivity matrix, and zero-acceleration offsets, respectively, and 5×10−3 degrees for the intrinsic angles.
Journal of Research (NIST JRES) -


acceleration, accelerometer, gravity, inertial, measurement, rotation, triaxial.


Geist, J. and Gaitan, M. (2022), Type-B uncertainty analysis of gravity-based determinations of triaxial-accelerometer properties by simulation of measurement errors, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed June 19, 2024)


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Created January 4, 2022, Updated November 29, 2022