SODAR

The Sodar (sonic detection and ranging) system is used to remotely measure the vertical turbulence structure and the wind profile of the lower layer of the atmosphere.

The Sodar system operates by emitting an acoustic pulse and receiving back the signal. Both the intensity and the Doppler (frequency) shift of the return signal are analyzed in order to determine the wind speed, wind direction and turbulent character of the atmosphere. A profile of the atmosphere as a function of height can be obtained by analyzing the return signal at a series of times following the transmission of each pulse. The return signal recorded at any particular delay time provides atmospheric data for a height that can be calculated based on the speed of sound. 

The Sodar system can perform measurements with a nominal maximum measuring height over 1000 m (not available in adverse weather conditions) with adjustable height resolution from 5 to 100m, the system frequency is 1500 and 2600 Hz, but optimum between 2000 and 2200 Hz. The horizontal wind components can be measured with resolution of ±50 m/s and vertical wind speed over ±10 m/s. The SODAR wind profiling can provide integration time of 600 to 1800 seconds typically and 7-12 ° beam width depending on frequency.

 The output parameters are: wind profiles, time series, vector plot, contour plot (smooth or raw).