Time of flight measurement system for an ultrasonic anemometer

A system for measuring Time of Flight (ToF) of wind using multiple ultrasonic sensors is introduced here. The time taken by the ultrasonic sound to travel from a transmitter to a receiver is expressed as the Time of Flight. The time interval between the transmission and reception decreases if the direction of wind aids the direction of propagation of sound. If the direction of propagation of sound is against the direction of wind, then the ToF will be more. The propagation of the ultrasonic sound is affected by the direction and intensity of the wind. Ultrasonic sound is transmitted between the transmitter and the receiver and vice versa. The ToF is measured for both directions using TDC1000-TDC7200EVM. Using Code Composer Studio, the ToF is calculated. The ToF measurement can be used to determine the three dimensional vector components of wind-u, v and w. From these components, the resultant wind velocity and direction can be obtained. The proposed system is aimed to have a better accuracy at lower cost when compared to the existing system.