A distinguishing method of the ultrasonic signal waveform starting point

According to the application of ultrasonic in wind speed, flow and liquid level measurement, a method about distinguishing ultrasonic signal waveform starting point was introduced. The high-powered DSP chip was chosen as the system's processor. The IIR band-pass digital filter was designed to eliminate disturbance. Marked change in fluctuation of ultrasonic signal sample was checked using the hypothesis testing to find the jumping off point of signal waveform. © The Authors.