Boundary-Layer Meteorology

, Volume 111, Issue 1, pp 33–54 | Cite as

Accuracy of Sonic Anemometers: Laminar Wind-Tunnel Calibrations Compared to Atmospheric In Situ Calibrations Against a Reference Instrument

  • Ulf Högström
  • Ann-Sofi Smedman


Two Gill Solent Ultrasonic anemometers, models 1012R2 and 1210R3, weretested in field parallel measurements against a windvane based hot-film anemometerwith additional sensors for temperature and wet-bulb temperature, the MIUU (MIUU:Meteorology Institute, Uppsala University) instrument. This instrument was shown toretain its precision from laminar wind-tunnel tests when used in atmospheric turbulentflow. This contrasts strongly to the observed results for the two sonic anemometers,which were first calibrated in laminar wind-tunnel flow. Individual three-dimensionalcalibration matrices were constructed, and were shown to reduce the remaining calibration uncertainty for the wind speed to 0.4–0.8% for all azimuths and for angles of attack within ±40°. In the field intercomparison tests of the sonics against the MIUU instrument, it was found that the precision not only of the mean wind speed but of all second-order moments studied (variances and covariances, with and without temperature) deteriorated by a factor of typically three to four. Most of the scatter appears to be random, but in the case of the wind speed, a clear dependence on wind direction is found as well. It is concluded that the correction for the effect of the vertical supporting rods of the R2 and R3 instruments, which gives nearly perfect agreement for laminar flow, does not work entirely satisfactory in the natural turbulent flow. This, in turn, is likely to be so because of high sensitivity of the wake behind the cylindrical supporting rods to the character of the approach flow.

Field intercomparison test Flow distortion Sonic anemometers Turbulence instrument test 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bergström, H. and Högström, U.: 1987, 'Calibration of a Three-Axial Fiber-Film System for Meteorological Turbulence Measurements', Dantec Information 5, 16–20.Google Scholar
  2. Daily, J. W. and Harleman, D. R. F.: 1966, Fluid Dynamics, Addison-Wesley Publ. Co., Reading, MA, 454 pp.Google Scholar
  3. Foken, T., Dlugi, R., and Kramm, G.: 1995, 'On the Determination of Dry Deposition and Emission of Gaseous Compounds at the Biosphere-Atmosphere Interface', Meteorol. Z. 4, 91–118.Google Scholar
  4. Gill Instruments Ltd.: 1992, 3 Axis Research Ultrasonic Anemometer, Product Specification. Issue 4.1. Gill Instruments Ltd., Saltmark Park, 67 Gosport Street, Lymington, Hampshire SO41 9EG, Great Britain. Doc. 1012-PS-0040, 40 pp.Google Scholar
  5. Gill Instruments Ltd.: 1998, User Manual and Product Specification, Omnidirectional (R3) and Asymmetric (R3A) Research Ultrasonic Anemometer. Gill Instruments Ltd., Saltmark Park, 67 Gosport Street, Lymington, Hampshire SO41 9EG, Great Britain. Doc. No. 1210-PS-0002-Iss 4, 38 pp.Google Scholar
  6. Grelle, A. and Lindroth, A.: 1994, 'Flow Distortion by a Solent Sonic Anemometer: Wind Tunnel Calibration and its Assessment for Flux Measurements over Forest and Field', J. Atmos. Oceanic Tech. 11, 1529–1542.Google Scholar
  7. Grelle, A. and Lindroth, A.: 1996, 'Eddy-Correlation System for Long-Term Monitoring of Fluxes of Heat, Water Vapour and CO2. Global Change Biol. 2, 297–307.Google Scholar
  8. Högström, U.: 1974, 'A Field Study of the Turbulent Fluxes of Heat, Water Vapour and Momentum at a “Typical” Agricultural Site', Quart. J. Roy. Meteorol. Soc. 100, 624–639.Google Scholar
  9. Högström, U.: 1982, 'A Critical Evaluation of the Aerodynamical Error of a Turbulence Instrument', J. Appl. Meteorol. 21, 1838–1844.Google Scholar
  10. Högström, U.: 2001, Results of Turbulence Instrument Intercomparison in the Field, MIUU Autoflux Report I. Department of Earth Sciences, Meteorology, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden. 33 pp. Also available on the Internet: Scholar
  11. Högström, U. and Bergström, H.: 1996, 'Organized Structures in the Near-Neutral Atmospheric Surface Layer', J. Atmos. Sci. 53, 2452–2464.Google Scholar
  12. Högström, U., Bergström, H., Smedman, A., Halldin, S., and Lindroth, A.: 1989, 'Turbulent Exchange above a Pine Forest, I: Fluxes and Gradients', Boundary-Layer Meteorol. 49, 197–217.Google Scholar
  13. Högström, U., Enger, L., and Knudsen, K.: 1980, A Complete System for Probing the Detailed Structure of Atmospheric Boundary Layer Flow. Department of Meteorology, Uppsala University, Villavägen 16, SE-75236 Uppsala, Sweden. Report No. 60, 46 pp.Google Scholar
  14. Kaimal, J. C. and Gaynor, J. E.: 1991, 'Another Look at Sonic Anemometry', Boundary-Layer Meteorol. 56, 401–410.Google Scholar
  15. Lumley, J. L. and Panofsky, H. A.: 1964, The Structure of Atmospheric Turbulence, Interscience Publishers, 239 pp.Google Scholar
  16. McIlroy, I. C.: 1955, 'A Sensitive Temperature and Humidity Probe', Aust. J. Agric. Res. 6, 196–199.Google Scholar
  17. Smedman, A. and Lundin, K.: 1987, 'Influence of Sensor Configuration on Measurements of Dry and Wet Bulb Temperature Fluctuations', J. Atmos. Oceanic Tech. 4, 668–673.Google Scholar
  18. Smedman, A., Högström, U., Bergström, H., Rutgersson, A., Kahma, K. K., and Pettersson, H.: 1999, 'A Case Study of Air-Sea Interaction during Swell Conditions', J. Geophys. Res. 104, 25,833–25,851.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Ulf Högström
    • 1
  • Ann-Sofi Smedman
    • 1
  1. 1.Department of Earth Sciences, MeteorologyUppsala UniversityUppsalaSweden

Personalised recommendations