Abstract: An active sonar apparatus which emits a sound wave and detects a target object based on a sound reflected by this target object including an FFT part which performs the fast Fourier transform of the received sound wave to derive a frequency spectrum and outputs this as an FFT signal, a normalization part which normalizes the FFT signal and outputs this signal as a normalized signal, and a noise elimination unit which performs a plurality of smoothing processes to the normalized signal, combines the signals to which the smoothing processes are performed to generate a combined signal, and outputs the combined signal in which a noise received together with the reflected sound is suppressed.

Abstract: An active sonar apparatus which emits a sound wave and detects a target object based on a sound reflected by this target object including an FFT part which performs the fast Fourier transform of the received sound wave to derive a frequency spectrum and outputs this as an FFT signal, a normalization part which normalizes the FFT signal and outputs this signal as a normalized signal, and a noise elimination unit which performs a plurality of smoothing processes to the normalized signal, combines the signals to which the smoothing processes are performed to generate a combined signal, and outputs the combined signal in which a noise received together with the reflected sound is suppressed.