A probe is pointed in the direction from which the wind is blowing and a screen
displays the rate at which the wind is moving between two ultrasonic sensors. The readout is shown on an alphanumeric liquid crystal disptay (l.c.d.), the readings are displayed in metres per second, feet per second, kilometres
per hour and miles per hour. The resolution is to the nearest tenth of a metre
per second, from zero up to around 50mph and possibly higher values.