Roll and Pitch Corrections for a Shipboard Anemometer

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An anemometer is an instrument which measures wind speed and direction. Ideally, an anemometer would measure solely the true wind, but in practice anemometers measure the vector sum of the true wind and the wind induced by the motion of the instrument. For anemometers mounted on ships, the pitch and roll of the ship is an important source of induced wind, but this effect has never been specifically investigated. In this project, I first explored the magnitude of the roll effect to determine whether or not it is worth correcting. Second, I investigated this effect for a Flush Air Data System (FADS) anemometer designed by researchers at NASA Ames Research Center. The anemometer was mounted in a wind tunnel and oscillated and the wind speeds measured were analyzed to evaluate the robustness of the system. The experiment was insufficient to judge the FADS anemometer’s performance, but the theoretical work demonstrated that the effect of pitch and roll is well worth examining further.