The Solent HS Ultrasonic Anemometer/Thermometer
For several decades, ultrasonic
anemometers-thermometers (so-called sonics) have been in use for atmospheric
turbulence measurements mainly for research and monitoring of the atmospheric
surface layer. A sonic provides the sound velocity and the wind velocity
along various, typically three, collocated paths. Typical spatial and
temporal resolutions are tens of centimeters and tens of milliseconds. The
precision of wind and temperature is on the order of a few centimeters per
second and a few tens of millikelvins, respectively. The measurement
principle is based on sound waves, which are sequentially transmitted between
two transducers along the paths (A, B, and C in Fig. 1). The time taken for a
sound wave from one transducer to another and for a wave to return over the
known distance is measured. From these measurements the flow velocity along
the path and the speed of sound can be derived. A detailed discussion of the
performance of the Solent HS, which is used on ACTOS can be found in Siebert
and Muschinski (2003). The influence of cloud droplets on sonic measurements
was investigated by Siebert and Teichmann (2000).
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| Figure 1: Sensor head of the Solent HS,
manufactured by Gill Inc., Lymongton, U.K. . |
Last Modification: 2006-05-18
