The Use of WOTANs as Wind Sensors

Calibration has proven to be a major hurdle in obtaining useful wind speeds from the five CASP WOTANs: wind and wave modellers demand in wind speed, while current WOTAN accuracies can do no better than . This contribution describes efforts to narrow and quantify the error bounds of WOTANs as marine wind speed sensors. It will describe recalibration of the transducers and A/D converters and allowance for variations of the acoustic ray paths and attenuation with measured sound velocity profiles. Expected error bounds are found to be between 5 and 10 %. Derived wind statistics for the CASP area are in preparation and will be compared with the CASP in situ measurements of wind. A proposed experiment will allow comparisons of WOTANs at different depths mounted above sea bottoms of various acoustic reflectivities against meteorological buoys.