Monostatic multi-tone triaxial Doppler SODAR (which stands for “SOnic Detection And Ranging) is an active remote sensing instrument capable of retrieving both the three-dimensional wind filed and the thermodynamic structure up to the first 1000 m of atmosphere. SODAR systems principle of operation is based on the interaction of acoustic waves with the atmosphere: short sound pulses (typically between 50-300 ms at 1-3 kHz) are emitted in the atmosphere, and the echoed signals scattered back by the small-scale thermal turbulence from different atmospheric layers are recorded. In the monostatic configuration, the transmitter and the receiver are co-located, and oriented along the same axis. The intensity and the Doppler shift of the returned signal are used to retrieve, respectively, the atmospheric thermal turbulence and the wind radial velocity, that is the wind velocity along the axes of the antenna. Although the thermal structure and the vertical velocity could be retrieved using a single vertically oriented beam, a three-dimensional wind profile needs at least three beams oriented along different axis.
The SODAR working in BAQUNIN Super Site is in the triaxial configuration, allowing to retrieve vertical and horizontal wind velocity. The instrument is operative since 2014.
REF
Casadio, S., M.P. Rao, G. Fiocco, M. Cacciani, A. di Sarra, D. Fuà, and P. Castracane, Estimation of atmospheric water vapor flux profiles in the nocturnal unstable urban boundary layer with Doppler sodar and Raman lidar, Boundary-Layer Meteorol., 102, 39-62, 2002
Casadio, S., A. di Sarra, D. Fuà, M.P. Rao, and G. Fiocco
Raman lidar and Doppler sodar observations of the nocturnal urban boundary layer at Rome, Italy, during 1994 and 1995, in Advances in Atmospheric Remote Sensing with Lidar
(Ansmann, Neuber, Rairoux and Wandinger eds.), Springer-Verlag, 27-30, 1997
PI: Marco Cacciani, marco.cacciani@uniroma1.it