Flywheel calibration of a continuous-wave coherent Doppler wind lidar

Anders Tegtmeier Pedersen, Michael Courtney*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

11 Downloads (Pure)

Abstract

A rig for calibrating a continuous-wave coherent Doppler wind lidar has been constructed. The rig consists of a rotating flywheel on a frame together with an adjustable lidar telescope. The laser beam points toward the rim of the wheel in a plane perpendicular to the wheel s rotation axis, and it can be tilted up and down along the wheel s periphery and thereby measure different projections of the tangential speed. The angular speed of the wheel is measured using a high-precision measuring ring fitted to the periphery of the wheel and synchronously logged together with the lidar speed. A simple geometrical model shows that there is a linear relationship between the measured line-of-sight speed and the beam tilt angle, and this is utilised to extrapolate to the tangential speed as measured by the lidar. An analysis of the uncertainties based on the model shows that a standard uncertainty on the measurement of about 0.1% can be achieved, but also that the main source of uncertainty is the width of the laser beam and its associated uncertainty. Measurements performed with different beam widths confirm this. Other measurements with a minimised beam radius show that themethod in this case performs about equally well for all the tested reference speeds ranging from about 3 to 18 m s-1.
Original languageEnglish
JournalAtmospheric Measurement Techniques
Volume14
Issue number2
Pages (from-to)889-903
Number of pages15
ISSN1867-1381
DOIs
Publication statusPublished - 2021

Fingerprint

Dive into the research topics of 'Flywheel calibration of a continuous-wave coherent Doppler wind lidar'. Together they form a unique fingerprint.

Cite this