A new ultrasonic anemometer which is used to measure low-level wind speed and direction is designed.The principle of the ultrasonic wind measurement is described

and the cross-correlation time delay estimation algorithm of system is analyzed.System configuration and timing controll of ultrasonic anemometer are described in detail.Experiments testify the system can accurately measure wind speed and direction.It also has others advantages

such as fast frequency response

good reliability

etc.So it can be used for realtime monitoring of the situation of the low-level wind field at airport.