A method to assess the accuracy of sonic anemometer measurements

Alfredo Peña*, Ebba Dellwik, Jakob Mann

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

We propose a method to assess the accuracy of atmospheric turbulence measurements performed by sonic anemometers and test it by analysis of measurements from two commonly used sonic anemometers, a Metek USA-1 and a Campbell CSAT3, at two locations in Denmark. The method relies on the estimation of the ratio of the vertical to the along-wind velocity power spectrum within the inertial subrange and does not require the use of another measurement as reference. When we correct the USA-1 to account for three-dimensional flow-distortion effects, as recommended by Metek GmbH, the ratio is very close to 4/3 as expected from Kolmogorov's hypothesis, whereas non-corrected data show a ratio close to 1. For the CSAT3, non-corrected data show a ratio close to 1.1 for the two sites and for wind directions where the instrument is not directly affected by the mast. After applying a previously suggested flow-distortion correction, the ratio increases up to approximate to 1.2, implying that the effect of flow distortion in this instrument is still not properly accounted for.
Original languageEnglish
JournalAtmospheric Measurement Techniques
Volume12
Issue number1
Pages (from-to)237-252
Number of pages16
ISSN1867-1381
DOIs
Publication statusPublished - 2019

Cite this

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title = "A method to assess the accuracy of sonic anemometer measurements",
abstract = "We propose a method to assess the accuracy of atmospheric turbulence measurements performed by sonic anemometers and test it by analysis of measurements from two commonly used sonic anemometers, a Metek USA-1 and a Campbell CSAT3, at two locations in Denmark. The method relies on the estimation of the ratio of the vertical to the along-wind velocity power spectrum within the inertial subrange and does not require the use of another measurement as reference. When we correct the USA-1 to account for three-dimensional flow-distortion effects, as recommended by Metek GmbH, the ratio is very close to 4/3 as expected from Kolmogorov's hypothesis, whereas non-corrected data show a ratio close to 1. For the CSAT3, non-corrected data show a ratio close to 1.1 for the two sites and for wind directions where the instrument is not directly affected by the mast. After applying a previously suggested flow-distortion correction, the ratio increases up to approximate to 1.2, implying that the effect of flow distortion in this instrument is still not properly accounted for.",
author = "Alfredo Pe{\~n}a and Ebba Dellwik and Jakob Mann",
year = "2019",
doi = "10.5194/amt-12-237-2019",
language = "English",
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pages = "237--252",
journal = "Atmospheric Measurement Techniques",
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A method to assess the accuracy of sonic anemometer measurements. / Peña, Alfredo; Dellwik, Ebba; Mann, Jakob.

In: Atmospheric Measurement Techniques, Vol. 12, No. 1, 2019, p. 237-252.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - A method to assess the accuracy of sonic anemometer measurements

AU - Peña, Alfredo

AU - Dellwik, Ebba

AU - Mann, Jakob

PY - 2019

Y1 - 2019

N2 - We propose a method to assess the accuracy of atmospheric turbulence measurements performed by sonic anemometers and test it by analysis of measurements from two commonly used sonic anemometers, a Metek USA-1 and a Campbell CSAT3, at two locations in Denmark. The method relies on the estimation of the ratio of the vertical to the along-wind velocity power spectrum within the inertial subrange and does not require the use of another measurement as reference. When we correct the USA-1 to account for three-dimensional flow-distortion effects, as recommended by Metek GmbH, the ratio is very close to 4/3 as expected from Kolmogorov's hypothesis, whereas non-corrected data show a ratio close to 1. For the CSAT3, non-corrected data show a ratio close to 1.1 for the two sites and for wind directions where the instrument is not directly affected by the mast. After applying a previously suggested flow-distortion correction, the ratio increases up to approximate to 1.2, implying that the effect of flow distortion in this instrument is still not properly accounted for.

AB - We propose a method to assess the accuracy of atmospheric turbulence measurements performed by sonic anemometers and test it by analysis of measurements from two commonly used sonic anemometers, a Metek USA-1 and a Campbell CSAT3, at two locations in Denmark. The method relies on the estimation of the ratio of the vertical to the along-wind velocity power spectrum within the inertial subrange and does not require the use of another measurement as reference. When we correct the USA-1 to account for three-dimensional flow-distortion effects, as recommended by Metek GmbH, the ratio is very close to 4/3 as expected from Kolmogorov's hypothesis, whereas non-corrected data show a ratio close to 1. For the CSAT3, non-corrected data show a ratio close to 1.1 for the two sites and for wind directions where the instrument is not directly affected by the mast. After applying a previously suggested flow-distortion correction, the ratio increases up to approximate to 1.2, implying that the effect of flow distortion in this instrument is still not properly accounted for.

U2 - 10.5194/amt-12-237-2019

DO - 10.5194/amt-12-237-2019

M3 - Journal article

VL - 12

SP - 237

EP - 252

JO - Atmospheric Measurement Techniques

JF - Atmospheric Measurement Techniques

SN - 1867-1381

IS - 1

ER -