Identify how wind speed and wind direction are measured

Measuring wind speed with a three-cup, handheld anemometer. The square plate at the back is a vane that aligns itself with the wind so you can measure wind direction too. This model, used by the US Navy, is an Ames RVM 96 B capable of measuring wind speeds up to about 50 m/s (180 km/h or 112 mph).