Ultrasonic wind vector measurement based on quadratic correlation two-frequency phase method.

A proposed method for measuring ultrasonic wind speed and direction utilizes the quadratic correlation phase method to address limited range issues and low measurement accuracy associated with the phase difference method when the signal-to-noise ratio is low. First, the proposed method uses quadratic correlation method combined with the four-step phase shift method to estimate the phase difference based on wind measuring structure of the opposing-type Array Structures. Then, the two-frequency phase difference method extends the measurement range of ultrasonic wind speed and direction. Finally, we also built an ultrasonic wind measurement system and perform practical tests, showing that the maximum measurement errors for wind speed and direction angles are within 0.28m/s and 2.8°, which essentially conforms to the ultrasonic anemometer's design requirements.