The sonic anemometers are based on the measurement of flight time of
high-frequency ultrasonic pulses between pairs of transducers. The duration of the
flight time depends on the sum of the air sound speed with the air velocity along the
flight path.
Fig. 3.10 Sonic anemometer (support in the background) and open-path carbon and water vapor
analyzer installed in the field
Fig. 3.11 Sonic anemometer and open-path carbon and water vapour analyser (left), with
close-up view (right) installed in the field
3.7 Eddy Covariance Method
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