Premium
On the accuracy of retrieved wind information from Doppler lidar observations
Author(s) -
Davies F.,
Collier C. G.,
Bozier K. E.,
Pearson G. N.
Publication year - 2003
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1256/qj.01.126
Subject(s) - lidar , geology , perpendicular , ridge , turbulence , wind speed , elevation (ballistics) , doppler effect , geodesy , range (aeronautics) , boundary layer , turbulence kinetic energy , remote sensing , meteorology , optics , physics , geometry , materials science , mechanics , mathematics , paleontology , astronomy , composite material
A single pulsed Doppler lidar was successfully deployed to measure air flow and turbulence over the Malvern hills, Worcester, UK. The DERA Malvern lidar used was a $\hbox{CO}_{2} \ 10.6\ \mu \hbox{m}$ pulsed Doppler lidar. The lidar pulse repetition rate was 120 Hz and had a pulse duration of $0.6\ \mu \hbox{s}$ . The system was set up to have 41 range gates with range resolution of 112 m. This gave a theoretical maximum range of approximately 4.6 km. The lidar site was 2 km east of the Malvern hill ridge which runs in a north–south direction and is approximately 6 km long. The maximum height of the ridge is 430 m. Two elevation scans (Range–Height Indicators) were carried out parallel and perpendicular to the mean surface flow. Since the surface wind was primarily westerly the scans were carried out perpendicular and parallel to the ridge of the Malvern hills. The data were analysed and horizontal winds, vertical winds and turbulent fluxes were calculated for profiles throughout the boundary layer. As an aid to evaluating the errors associated with the derivation of velocity and turbulence profiles, data from a simple idealized profile was also analysed using the same method. The error analysis shows that wind velocity profiles can be derived to an accuracy of 0.24 m s −1 in the horizontal and 0.3 m s −1 in the vertical up to a height of 2500 m. The potential for lidars to make turbulence measurements, over a wide area, through the whole depth of the planetary boundary layer and over durations from seconds to hours is discussed. Copyright © 2003 Royal Meteorological Society