scholarly journals MICROSCOPE: systematic errors

2022 ◽  
Author(s):  
Manuel Rodrigues ◽  
Pierre Touboul ◽  
Gilles Metris ◽  
Alain Robert ◽  
Oceane Dhuicque ◽  
...  
Keyword(s):  
Systematic Errors ◽  
Gravity Gradient ◽  
Error Sources ◽  
Weak Equivalence Principle ◽  
Satellite Design ◽  
External Perturbations ◽  
Estimation Uncertainty ◽  
Magnetic Perturbations ◽  
Internal Sources ◽  
Parameter Estimation Uncertainty

Abstract The MICROSCOPE mission aims to test the Weak Equivalence Principle (WEP) in orbit with an unprecendented precision of 10-15 on the Eövös parameter thanks to electrostatic accelerometers on board a drag-free microsatellite. The precision of the test is determined by statistical errors, due to the environment and instrument noises, and by systematic errors to which this paper is devoted. Sytematic error sources can be divided into three categories: external perturbations, such as the residual atmospheric drag or the gravity gradient at the satellite altitude, perturbations linked to the satellite design, such as thermal or magnetic perturbations, and perturbations from the instrument internal sources. Each systematic error is evaluated or bounded in order to set a reliable upper bound on the WEP parameter estimation uncertainty.

scholarly journals Neglect Of Parameter Estimation Uncertainty Can Significantly Overestimate Structural Reliability

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Árpád Rózsás ◽  
Miroslav Sýkora
Keyword(s):  
Parameter Estimation ◽  
Bayesian Statistics ◽  
Failure Probability ◽  
Structural Reliability ◽  
Probabilistic Models ◽  
Estimation Uncertainty ◽  
Point Estimates ◽  
Distribution Parameters ◽  
Order Of Magnitude ◽  
Parameter Estimation Uncertainty

Abstract Parameter estimation uncertainty is often neglected in reliability studies, i.e. point estimates of distribution parameters are used for representative fractiles, and in probabilistic models. A numerical example examines the effect of this uncertainty on structural reliability using Bayesian statistics. The study reveals that the neglect of parameter estimation uncertainty might lead to an order of magnitude underestimation of failure probability.

Error sources and models of the laser tracker without a beam steering mirror

2021 ◽  
Author(s):  
Radoslav Choleva ◽  
Alojz Kopáčik
Keyword(s):  
Measurement Accuracy ◽  
Beam Steering ◽  
Systematic Errors ◽  
Error Modeling ◽  
Laser Tracker ◽  
High Demand ◽  
Error Sources ◽  
Error Models ◽  
Measurement Results

AbstractThe laser tracker is a widely used instrument in many industrial and metrological applications with high demand measurement accuracy. Imperfections in construction and misalignment of individual parts deliver systematic errors in the measurement results. All error sources need to be identified and reduced to the minimum to achieve the best possible accuracy. The paper summarizes error sources of the laser tracker without beam steering mirror with emphasis on error modeling. Descriptions of error models are provided for the static and kinematic type of measurement.

scholarly journals Trends of solar ultraviolet irradiance at Barrow, Alaska, and the effect of measurement uncertainties on trend detection

2011 ◽  
Vol 11 (9) ◽  
pp. 26617-26655 ◽  
Author(s):  
G. Bernhard
Keyword(s):  
Time Series ◽  
Systematic Errors ◽  
Correction Method ◽  
Natural Variability ◽  
Trend Detection ◽  
Transfer Model ◽  
Error Sources ◽  
Model Calculations ◽  
Uv Index ◽  
Measurement Uncertainties

Abstract. Spectral ultraviolet (UV) irradiance has been observed near Barrow, Alaska (71° N, 157° W) between 1991 and 2011 with an SUV-100 spectroradiometer. The instrument was historically part of the US. National Science Foundation's UV Monitoring Network and is now a component of NSF's Arctic Observing Network. From these measurements, trends in monthly average irradiance and their uncertainties were calculated. The analysis focuses on two quantities, the UV Index (which is affected by atmospheric ozone concentrations) and irradiance at 345 nm (which is virtually insensitive to ozone). Uncertainties of trend estimates depend on variations in the data due to (1) natural variability, (2) systematic and random errors of the measurements, and (3) uncertainties caused by gaps in the time series. Using radiative transfer model calculations, systematic errors of the measurements were detected and corrected. Different correction schemes were tested to quantify the sensitivity of the trend estimates on the treatment of systematic errors. Depending on the correction method, estimates of decadal trends changed between 1.5% and 2.9%. Uncertainties in the trend estimates caused by error sources (2) and (3) were set into relation with the overall uncertainty of the trend determinations. Results show that these error sources are only relevant for February, March, and April when natural variability is low due to high surface albedo. This method of addressing measurement uncertainties in time series analysis is also applicable to other geophysical parameters. Trend estimates varied between −14% and +5% per decade and were significant (95.45% confidence level) only for the month of October. Depending on the correction method, October trends varied between −11.4% and −13.7% for irradiance at 345 nm and between −11.7% and −14.1% for the UV Index. These large trends are consistent with trends in short-wave (0.3–3.0 μm) solar irradiance measured with pyranometers at NOAA's Barrow Observatory and can be explained by a change in snow cover over the observation period: analysis of pyranometer data indicates that the first day of fall when albedo becomes larger than 0.6 after snow fall, and remains above 0.6 for the rest of the winter, has advanced with a statistically significant trend of 13.6 ± 9.7 days per decade.

scholarly journals Error sources in the force mode of the “PB2” Planck-Balance

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 53
Author(s):  
N. Rogge ◽  
C. Rothleitner ◽  
S. Lin ◽  
S. Vasilyan ◽  
T. Fröhlich ◽  
...  
Keyword(s):  
Systematic Errors ◽  
Error Sources ◽  
Force Mode ◽  
Class E

The PB2 Planck-Balance is a table-top Kibble balance, that is designed for the calibration of class E<sub>2</sub> weights in a range of 1 mg up to 100 g. This work presents typical systematic errors which have to be considered during the calibration and will show results for measurements with small masses.

scholarly journals FIRST DEGREE POLYNOMIAL FITTING FOR FORCES AND MOMENTS ON THE AERODYNAMIC TEST MODEL

2017 ◽  
Vol 14 (27) ◽  
pp. 97-104
Author(s):  
Itamar Magno BARBOSA ◽  
Bogos Nubar SISMANOGLU ◽  
Pedro Ivo Pinto OLIVEIRA
Keyword(s):  
Systematic Errors ◽  
Standard Uncertainty ◽  
Test Model ◽  
Aerodynamic Forces ◽  
Degree Polynomial ◽  
Multivariate Polynomial ◽  
Error Sources ◽  
Iso 17025 ◽  
Polynomial Modeling ◽  
Aerodynamic Test

We analyzed a multivariate polynomial model related to Calibration Curve of an External Balance of Aerodynamic Forces. The ISO 17025 explicit that it is not always possible to calculate rigorously the measurement uncertainty in Test Laboratories. The test nature circumscribes error sources control, time and costs. This fact implies that choosing a Mathematical Modeling is also an affair of productivity management, not only a computational matter. For a First Degree Polynomial Modeling we evaluated the Statistical Performance Index, as to Measurement Bias, Standard Uncertainty, X – Square and Uncertainties and Co – Variances Matrix. We evaluated the Measurement System Repeatability through successive resembling Calibrations. We showed Aerodynamic Forces that may be considered individual ones trough uncertainties and systematic errors. In the same way, bias was verified through systematic error analysis, i. e., in what conditions the polynomial intersects at the origin or not.

scholarly journals Trends of solar ultraviolet irradiance at Barrow, Alaska, and the effect of measurement uncertainties on trend detection

2011 ◽  
Vol 11 (24) ◽  
pp. 13029-13045 ◽  
Author(s):  
G. Bernhard
Keyword(s):  
Time Series ◽  
Systematic Errors ◽  
Correction Method ◽  
Natural Variability ◽  
Trend Detection ◽  
Transfer Model ◽  
Error Sources ◽  
Model Calculations ◽  
Uv Index ◽  
Measurement Uncertainties

Abstract. Spectral ultraviolet (UV) irradiance has been observed near Barrow, Alaska (71° N, 157° W) between 1991 and 2011 with an SUV-100 spectroradiometer. The instrument was historically part of the US National Science Foundation's UV Monitoring Network and is now a component of NSF's Arctic Observing Network. From these measurements, trends in monthly average irradiance and their uncertainties were calculated. The analysis focuses on two quantities, the UV Index (which is affected by atmospheric ozone concentrations) and irradiance at 345 nm (which is virtually insensitive to ozone). Uncertainties of trend estimates depend on variations in the data due to (1) natural variability, (2) systematic and random errors of the measurements, and (3) uncertainties caused by gaps in the time series. Using radiative transfer model calculations, systematic errors of the measurements were detected and corrected. Different correction schemes were tested to quantify the sensitivity of the trend estimates on the treatment of systematic errors. Depending on the correction method, estimates of decadal trends changed between 1.5% and 2.9%. Uncertainties in the trend estimates caused by error sources (2) and (3) were set into relation with the overall uncertainty of the trend determinations. Results show that these error sources are only relevant for February, March, and April when natural variability is low due to high surface albedo. This method of addressing measurement uncertainties in time series analysis is also applicable to other geophysical parameters. Trend estimates varied between −14% and +5% per decade and were significant (95.45% confidence level) only for the month of October. Depending on the correction method, October trends varied between −11.4% and −13.7% for irradiance at 345 nm and between −11.7% and −14.1% for the UV Index. These large trends are consistent with trends in short-wave (0.3–3.0 μm) solar irradiance measured with pyranometers at NOAA's Barrow Observatory and can be explained by a change in snow cover over the observation period: analysis of pyranometer data indicates that the first day of fall when albedo becomes larger than 0.6 after snow fall, and remains above 0.6 for the rest of the winter, has advanced with a statistically significant trend of 13.6 ± 9.7 days per decade.

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