Design of rapid measurement of acoustic Doppler velocity

In traditional Doppler velocity measurement, mixing quadrature and low-pass filtering are generally implemented in software, which results in relatively long measurement time and low accuracy. In order to solve the above-mentioned, STM32H743 single chip computer with faster operation speed and larger memory capacity has been used as the main control chip, and a Doppler velocity profiler is designed by using signal mixing, orthogonal and FIR low-pass filtering in the hardware circuit, which greatly reduces the CPU operation time and improves the measurement efficiency. At the same time, FFT algorithm has been used to analyze the signal quality, and autocorrelation algorithm has been used to calculate the velocity of each layer. Through the experiment, the frequency deviation and velocity are analyzed. The results show that the design of the system can meet the requirements of accurate measurement in actual small streams, and it is feasible.