sonic anemometer Articles

  • Minimizing flow distortion errors in a sonic anemometer

    This paper describes a simple approach to minimizing probe-induced flow distortion errors in a three-axis sonic anemometer. By separating the three axes, mutual interference between the transducers and supports in the three arrays is reduced. Only a transducer shadow correction determined from wind tunnel tests is needed to obtain measurements that are virtually insensitive to probe orientation ...

  • Why Does the Non-Orthogonal Sonic Anemometer Underestimate

    The performance of non-orthogonal sonic anemometers has been the subject of much discussion in recent years.  It followed findings that they underestimated vertical winds and vertical heat fluxes by 10-15%.  For agricultural and forestry scientists who depended on them for their large-scale energy balance studies this was a bad surprise.  They had collected turbulence data from ...

  • Sonic Thermometry

    Sonic anemometers have had extensive use in the scientific community. These instruments are used to measure atmospheric parameters that most rotating instruments cannot. Wind speed and wind direction or individual axes of wind velocity are most commonly measured. Along with these measurements, another parameter can be extracted from the sonic anemometer (i.e.), sonic temperature. Since the ...

  • Comparisons of models with data: effects of averaging time as indicated by sonic anemometer measurements

    For continuous sources, plots of predicted against observed gas concentrations often display considerable scatter. These differences are apparent even when the averaging times for the models and data match. Possible sources of error in the observations are shifts in direction of the mean wind or disturbance by intermediate- and large-scale eddies. Errors in predictions may arise from the ...


    By Inderscience Publishers

  • Another look at sonic thermometry

    Abstract. In this note we reassess the role of sonic thermometry in boundary-layer studies. The sonic temperature signal, when corrected for crosswind velocity contamination, very closely approximates the virtual temperature of air. This variable is needed for many boundary-layer calculations. We describe preliminary tests with a new sonic anemometer-thermometer that performs the velocity ...

  • Sonic temperature significance and limitations

    The ATI sonic thermometer measures temperature from transit times t1 and t2 measured along the vertical path of the anemometer's probe. They are the times taken by sound pulses to traverse the 15-cm acoustic path in opposite directions; (these same transit times are used also for computing the vertical wind component). The instrument exploits the strong dependence that exists between the speed ...

  • Metek Introduces the New Multi-Path Ultrasonic Anemometers

    Our news report about recent instrumentations or measurements of our customers which might be of special interest for other web site visitors. The reports are added on the fly whenever we have received such information. The experienced support is highly welcome and appreciated. Metek is proud to present the new members of the uSonic-family: The ultrasonic anemometers uSonic-3 Class A ...

  • Effects of spatial filtering, prefiltering, and aliasing in measurements from applied technologies` Sonic K-Probe

    The Applied Technologies' Inc. (ATI) K-probe measures wind components along three mutually orthogonal axes separated spatially from each other to minimize flow distortion errors. The sonic anemometer samples the wind at a 100-Hz rate but constructs 0.1-s (10-point) non-overlapping block averages to provide. a 10-Hz data train for internal processing. This digital prefiltering is designed to ...

  • Effects of averaging time on predicted gas concentrations

    The potential consequences of a particular gaseous emission usually relate to a specific averaging time. However, the averaging time associated with gas monitoring data in the region of a discharge may differ from the averaging time implicit in a model employed to predict the concentration resulting from that emission. Tables of factors exist for taking account of such differences and recent ...


    By Inderscience Publishers

  • Verification of wind energy related measurements with a SODAR system

    Abstract Complex terrain and growing wind energy converters (WEC) in wind parks generate increasing interest in determining wind profiles and turbulence besides the general forecast of annual energy production. Increasing hub heights and growing rotor diameters of advanced WEC make SODAR systems a valuable alternative to meteorological towers. SODAR systems provide wind profiles as well as ...

  • Basic tests for checking validity of field data

    The following guidelines are suggested for verifying micrometeorological data gathered in field experiments. It is assumed, for simplicity, that the observations being tested are made over open, relatively flat and uniform terrain, with small roughness elements. It is also assumed that the sensors and the data acquisition and recording hardware are basically sound and that the purpose of the ...

  • Some thoughts on in-situ flux measurement in the atmospheric surface layer

    Due to its complexity, the state of a turbulent atmosphere can only be described using statistical quantities such as means, variances, and covariances. Computation of these statistical quantities, particularly those of higher order, must be done with considerable care. This is particularly true if the statistics are used to depict heat and momentum fluxes. This note contains considerations that ...

  • A simple methodology for surface layer characterization during diabatic extremes

    Increased global environmental awareness has fostered widespread use of remote automated weather station (RAWS) networks to monitor meteorological conditions, and reliance on atmospheric dispersion modeling for decisions concerning pollutant dispersion. Dispersion models require as input a characterization of surface layer (SL) heat and momentum fluxes and turbulence. Characterization of these ...

  • Estimates of lateral dispersion parameters in low wind speed conditions

    Wind speed time series recorded during stable low wind speed conditions are typically non–stationary, with large horizontal oscillations, commonly known as meandering. In this paper, two wavelet–based methods are proposed to obtain lateral dispersion coefficients from such time series. These methods, associated with a specific wind model, have been tested by using wind velocities recorded, with ...


    By Inderscience Publishers

  • A preliminary analysis of measurements from a near-field pollutants dispersion campaign in a stratified surface layer

    In order to study pollutants dispersion in a stably stratified surface layer at small scales, a pollutants dispersion field experiment programme is being conducted on the site SIRTA in the southern suburb of Paris. In a preliminary campaign held during the winter of 2012 with continuous gas releases, we had 12 ultrasonic anemometers measuring wind velocity and temperature at 10 Hz, and six ...


    By Inderscience Publishers

  • A simple notch filter for removing high frequency noise in atmospheric measurements

    The experimenter occasionally encounters high-frequency (> 1 Hz) contamination in sonic anemometer data that adversely affects higher-order moment calculations. One has the option of applying a low-pass filter (either a simple, equally weighted moving average filter or any one of the sharper cut-off versions available today) to eliminate not only the unwanted frequency, but all frequencies ...

  • Momentum Flux: Gross, Scalar, Alongwind, or Net?

    Modern micrometeorology is an amalgam of two traditions: one arises from field measurements in the open atmosphere and another from wind tunnel experiments. Early micrometeorological field work, and even relatively recent studies (viz. the von Karman constant experiments by Frenzen and Vogel, 1995), were done with precision cup anemometers, which can only provide a scalar speed measurement. Most ...

  • Consequences of oversampling

    Oversampling is generally perceived as an inefficient practice because of the redundancy it creates in the data, but rarely is it considered detrimental. The resulting increase in bandwidth seldom if ever, provides new information, as the signal is often badly attenuated and not very useful above a certain frequency. The decision to oversample is often based on the assumption that no undue harm ...

  • Amassing Wind Information

    Wind is a variable resource, but not an indecipherable one. Second Wind encourages harnessing the full range of wind sensing technologies that are available today. When it comes to wind information, much attention is focused on the choice of wind measurement technology and data collection practices in wind resource assessment and project design. Right now, wind data plays a limited role in the ...


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