A system and method involve determining the airspeed of a vehicle using the propagation time of an acoustic signal from a transmitter located at one end of the vehicle to a receiver located at the other end of the vehicle. A digital representation of the acoustic signal is created and stored within non-volatile memory within the transmitter, then converted into an electrical signal which is filtered, amplified, and input into a transducer contained within the transmitter. The transducer radiates an acoustic signal toward the receiver, which receives and filters the acoustic signal, converts it into a digital signal, and processes the digital signal to determine the acoustic signal propagation time. The acoustic signal may have a continuous wave form, a duty cycle of about 100%, a peak to average amplitude ratio of less than about 2.5, and Fourier components of substantially equal amplitude and random phase.