====== Sodar ====== //Mentor: J.H. Schween.// ===== Principle ===== A SODAR is a wind profiler based on the **so**nic **d**etecting **a**nd **r**anging principle. A sound is emitted and backscattered at inhomogeneities of the temperature field. Travel time of the backscattered sound signal is related to distance, Doppler shift gives the wind speed along the sound beam. Several tilted sound beams allow to infer the vector components of the wind. Strength of the reflected signal gives information about the turbulence intensity. ===== Instrument ===== {{:instruments:sodar:sodar_20080814.jpg?300|}}\\ [[http://www.metek.de/|METEK]] Doppler SODAR PCS.2000-64/MF at the [[http://www.tr32.de|TR32]] test site Selhausen managed by [[http://www.fz-juelich.de/|Research Center Jülich]] as part of the [[http://www.fz-juelich.de/icg/icg-4/index.php?index=500|FlowWatch]] project. ===== Data ===== [[http://www.uni-koeln.de/~jschween/tr32/sodar/|Current observations]] ===== History ===== ^ Period ^ Place ^ Project ^ | 08/2008 - today | [[http://www.fz-juelich.de/icg/icg-4/index.php?index=500|Selhausen]], Germany | [[http://www.tr32.de|TR32]] | ===== Specifications ===== ^ Parameter ^ Specification ^ Remark ^ | Frequencies / kHz | 1.493, 1.693, 1.893, 2.093, 2.293 | during daytime adjustable in 1.5-3 | | | 1.493, 1.893, 2.293 | during nightime | | Wavelengths / mm | 228, 201, 180, 163, 148 | depends on speed of sound (cS), values here are for 15°C | | tilt angles / deg | 25, 22, 19, 18, 16 | depends on cS and frequency, see setup manual | | Pulse Peak Power / W | ? | | | Average Power / W | ? | | | Repetition Rate / Hz | ~.69 | Depends on cS and 'noise height' (zN) it is cS/zN | | Average every / min | 10 | Adjustable | | Pulse Width / ms | 58.7 | Depends on cS and dz (dz/cS) | | Range resolution / m | 20 | Adjustable in 5-50 | | Range / m | 400 | Adjustable | | lowest height / m | 30 | Adjustable | | noise height / m | 490 | Adjustable | | Accuracy horizontal wind | ± max(0.5m/s,10%) | | | Accuracy vertical wind | ± 0.1 m/s | | | Accuracy direction | ± 5° | | | Field-of-View Divergence | ? | Depends on many parameters | | Size / m³ | 2 x 2 x 2 | sound protection walls | | Average Power consumption / W | 380 | PC + loudspeaker unit | | Weight / kg | 120 | Antenna array alone | ===== Internal information ===== * [[:internal:instruments:sodar:sodar_log|Logbuch]] * [[:internal:instruments:sodar:readme_sodar|Readme]]