| 摘要 |
PROBLEM TO BE SOLVED: To efficiently suppress a noise and improve the detection accuracy of a target object even when the noise includes a plurality of frequency components.SOLUTION: An active sonar apparatus includes an FFT part which performs fast Fourier transform of a received sound wave to derive a frequency spectrum and outputs it as an FFT signal, a normalization part which normalizes the FFT signal and outputs the signal as a normalized signal, and a noise elimination unit which performs a plurality of smoothing processes to the normalized signal, and combines the signals to which the smoothing processes are performed to output the combined signal in which a noise received together with the reflected sound is suppressed. |
