Errors in windspeed measurements by rotation anemometers
Abstract
A perturbation theory approach of nonlinear mechanics is applied to the solution of a nonlinear rotation anemometer dynamic equation in a gusty wind. The first two terms of the perturbation series give a simplified equation for the windspeed overestimation by a rotation anemometer ( uerror) in terms of a wind velocity spectrum (or a correlation function). The equation agrees satisfactorily with all the known analytical or numerical solutions of rotation anemometer equations. It agrees, in particular, with recent theoretical estimations of the uerror magnitude by Kondo et al. (1971) and Hyson (1972), but disagrees significantly with the experimental findings of Izumi and Barad (1970) and Högström (1974). The same approach is also used for the estimation of the influence of the vertical wind fluctuations on the rotation anemometer readings ( werror). It is shown that werror is usually of the same sign as uerror and that the sum of these both types of errors may be in some cases of the same order as an experimental windspeed overestimation observed by Izumi and Barad and by Högström. However, it seems probable that some additional types of errors contribute also to the real overspeeding of rotation anemometers in a gusty wind.
 Publication:

BoundaryLayer Meteorology
 Pub Date:
 March 1976
 DOI:
 10.1007/BF00218722
 Bibcode:
 1976BoLMe..10...15K
 Keywords:

 Anemometers;
 Equations Of Motion;
 Error Analysis;
 Perturbation Theory;
 Wind Velocity Measurement;
 Approximation;
 Numerical Analysis;
 Rotating Bodies;
 Sine Waves;
 Velocity Distribution;
 Instrumentation and Photography