Wind speed sensors

Wind speed is the speed of the air relative to the ground. It is a directional quantity, defined as a vector with a horizontal and a vertical component. In practice, however, this is usually limited to the horizontal component and categorized into wind strengths based on specific speed intervals. This makes it possible to process the speed vector in an application-oriented manner so that the relevant elements can then be entered into weather maps, for example. For certain applications, such as aviation, the vertical component of wind speed is also important, for example, to estimate updrafts for gliders or paragliders.

Wind speed can be estimated using a windsock or phenomenologically, for example, using the Beaufort scale. Updrafts can be estimated from cloud formations, and such easily linked clues are also helpful in numerous other special cases. A wind gun is used by artillery to determine the approximate wind speed at various altitudes.

Wind speed is usually measured more accurately using a small rotating anemometer, the cup anemometer. However, more accurate ultrasonic anemometers and SODAR systems are now available, which use the propagation of sound waves to measure wind speed and are thus often also capable of measuring vertical profiles.

The SODAR systems measure wind speeds from the ground up to heights of 200 m. This method can be used to accurately determine the elevation profile. However, the absolute accuracy is usually not sufficient for energy yield calculations for wind turbines.