A Dual-Frequency Phase Difference Method for Wind Speed and Direction Measurements Based on Second-Order Fractional Low-Order Covariance

We present a novel solution to the problems caused by the current single-frequency phase difference method's constrained measurement range and the low measurement accuracy in ultrasonic wind speed and direction measurements with impulse noise background. A dual-frequency phase difference method built on second-order fractional low-order covariance is used in the suggested method. First, we estimate the phase difference using a hybrid orthogonal method and the second-order fractional low-order covariance. The dual-frequency phase difference approach is then used to increase the measuring scope for ultrasonic wind direction and speed. We also build an ultrasonic wind measurement system and perform practical tests, showing that the maximum measurement errors for wind speed and direction angles are within 2.5% and 2.4°, which essentially satisfies the ultrasonic anemometer's design requirements.