Turbulence measurements using six lidar beams

Ameya Sathe, Jakob Mann

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Abstract

The use of wind lidars for measuring wind has increased significantly for wind energy purposes. The mean wind speed measurement using the velocity azimuth display (VAD) technique can now be carried out as reliably as the traditional instruments like the cup and sonic anemometers. Using the VAD technique the turbulence measurements are far from being reliable. Two mechanisms contribute
to systematic errors in the measurement of turbulence. One is the averaging of small scales of turbulence due to the volume within which lidars measure wind speed. The other is the contamination by the cross components of the Reynolds stress tensor, which arises because, in a VAD scan the lidar beams are combined to obtain different components of the wind field. In this work we demonstrate theoretically, how the contamination by the cross components can be avoided by using the measured variances of the line-of-sight velocities of six lidar beams. Under certain assumptions the volume averaging can then be avoided using the ensemble averaged line-ofsight Doppler velocity spectra. In this way, we can then in principle measure the true turbulence using six lidar beams.
Original languageEnglish
Title of host publicationExtended Abstracts of Presentations from the 16th International Symposium for the Advancement of Boundary-Layer Remote Sensing
PublisherSteering Committee of the 16th International Symposium for the Advancement of Boundary-Layer Remote Sensing
Publication date2012
Pages302-305
Publication statusPublished - 2012
Event16th International Symposium for the Advancement of Boundary-Layer Remote Sensing - Boulder, United States
Duration: 5 Jun 20128 Jun 2012
Conference number: 16
https://www.esrl.noaa.gov/psd/events/2012/isars/

Conference

Conference16th International Symposium for the Advancement of Boundary-Layer Remote Sensing
Number16
CountryUnited States
CityBoulder
Period05/06/201208/06/2012
Internet address

Cite this

Sathe, A., & Mann, J. (2012). Turbulence measurements using six lidar beams. In Extended Abstracts of Presentations from the 16th International Symposium for the Advancement of Boundary-Layer Remote Sensing (pp. 302-305). Steering Committee of the 16th International Symposium for the Advancement of Boundary-Layer Remote Sensing.