Speed measuring apparatus

摘要

A speed measuring apparatus includes a transmitter for transmitting an acoustic reference wave toward a moving-target, the acoustic reference wave being generated based on a reference signal with a predetermined frequency; a receiver for receiving acoustic reflection waves which are generated by the transmitted acoustic reference wave being deflected by the moving-target, converting the acoustic reflection waves to receiver signals, and outputting the receiver signals therefrom; a signal attenuating unit for selectively attenuating a signal component with the same frequency as the frequency of the reference signal in the receiver signals which are output from the receiver and outputting signals therefrom; a band pass filter unit for abstracting at least one Doppler signal component from the signals output from the signal attenuating unit; and a speed computing unit for computing the speed of the moving-target relative to the speed measuring apparatus, based on the Doppler signal component abstracted by the band pass filter unit. <IMAGE>