How is wind measured at this small U.S. airport? While launching gliders at Front Royal, VA (KFRR) over the weekend, a fellow pilot and I got curious about the airport's weather equipment.  We know that KFRR has local equipment to measure wind speed and direction. There is a screen in the FBO that shows a graphical readout of the wind situation.  However, it was not obvious looking at the equipment itself how this is done.  

Here are two pictures I took:





Nothing on either of these two pieces of equipment was actively spinning or being visibly affected by the wind.  At the time we has a 10-12 knot headwind almost directly down the runway.  This equipment is ~40 feet to the left of the runway threshold.

Question: Is one of the pieces of equipment I've photographed responsible for measuring wind speed? If so, how?
Ultrasonic anemometers are replacing the traditional cup anemometers in automated weather stations.  The sensor measures the time it takes for an ultrasonic pulse to travel between the probes, which is affected by wind speed. In your second image, the object directly above the lights appears to be an anemometer.



Source

Ultrasonic sensors have the advantage of no moving parts and lower maintenance requirements. Also, with additional probes, they can measure the wind in 3D.