1.5µm An innovative and compact 1.5 m lidar for the wind industry R. Parmentier, L. Sauvage, C. Aussibal, I.S. Stachlewska, M. Lardier Leosphere, Bat. 503, Centre Scientifique d’Orsay, Plateau du Moulon, 91400 ORSAY, France J-P. Cariou, M. Valla ONERA/DOTA, 91100 Palaiseau, France I. Antoniou, M.S. Courtney Wind Energy Department, Risoe National Laboratory, Technical University of Denmark, Frederiksborgvej 399, P.O. Box 49, DK-4000 Roskilde - Denmark Windcube TM real- it’ setup, is a new real-time wind profiler, it’s fast to setup, EZ to configure and compatible with months of unattended operation Aerosols r WindCubeTM Key benefits Vr EXTREME CONDITIONS r V Pulsed Lidar simultaneous, steady performances vs. altitude eye-safe; silent and discreet instrument ωl Range resolved 1.5 µm fibre laser source reliable, robust, low maintenance telecom components ωl + 2π fd measurement 10 min U, V, W, Vh, Direction User-friendly software σU , σV , σW , σVh Doppler shift pe 2Vr co Vhmin, Vhmax fd = l es λ Te Laser Interferometer Receiver Advanced signal processing leading to state of the art compatible measurement accuracy Local Oscillator Processing WindCubeTM specifications COMPACT, SILENT & DISCREET Pulsed Doppler Coherent lidar basics A laser pulse is sent through the atmosphere. All along its path, light is scattered by aerosols, dusts, water drops… We collect backscattered light and make it interfere with an optical local oscillator. Optical signal is digitized and processed to retrieve Doppler shift induced by aerosols’ motion. This is an absolute measurement of radial wind speed in the lidar line of sight. Range resolution comes from pulse propagation vs. time. 10min average Lidar horizontal wind speed compared to RISØ cup anemometers 3D wind vector retrieval 4 lines of sight are sequentially scanned to perform geometrical computation of 3D wind vector components (horizontal and vertical wind speeds, and direction). 160m met mast is several hundred Retrieved wind field corresponds to an average of ~25m thick atmosphere layer meters away from the WindCube and comparison is just indicative 160m centered on up to 10 user defined altitudes. Classical scanning cone angle is 30°and can be rapidly reduced to 15°for accurate wind profiling in complex terrain. 10min average Lidar horizontal wind direction compared with CEA-Saclay (FRANCE) USA-1 sonic anemometer at 60m & 100m. LEOSPHERE thanks CEA for WindcubeTM evaluation campaign performed in January-February 2007. Horizontal wind speed standard deviation at 116m 116m L_Usd115m=0.928 Cup_sd116m+0.043 WindCubeTM can operate under any weather conditions Theoretical lidar range exceeds 150m in most common visibility conditions. LEOSPHERE will offer a range increase by upgrading laser source power to 100m 100µJ in the near future. Prototype has been successfully experienced during Frankfurt CREDOS campaign performed by ONERA. Increasing pulse length can also increase measurement range: a 120m range gate would lead to a 500m max altitude with a 10 µJ pulse energy. Vertical wind speed standard deviation at 100m Benefit from EZ Software ! Real-Time data and statistics for selected 80m altitude March data altitude (m) availability (1Hz data, %) 60 99.1 100 98.2 150 95.9 200 87.7 Windcubetm data availability over March at RISØ Høvsøre test site (Denmark) 60m Site weather statistics: - T°min : 0° C - T°max : 16°C - precipitation 50mm - wind speed between 1 and 30 m/s more test site weather statistics available at: http://veaonline.risoe.dk/rodeo/ProjectOverview.aspx?&Project=4&Rnd=149049 CNR vs. range Real-Time horizontal wind speed profile Real-Time wind direction profile 676 data points acquired over March 2007 at Høvsøre test site (Denmark) dry weather data, wind direction between 240° -300°and 70° -110°(free sector) This work was partly funded by ADEME. wind speeds above 4m/s LEOSPHERE is very grateful to Laboratoire de Surveillance de l’Environnement at CEA-Saclay for providing met mast data at 60m and 100m. LEOSPHERE acknowledges people at RISØ for their help and availability during validation campaign; special thanks to Bjarne Soenderskov and Peter Lind.
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