P002

Sonar Signal Processing Based on the Harmonic Wavelet Transform

A0002 Takaaki Musha 5th Research Center, Technical Research & Development Institute, Japan Defence Agency, Japan

A0003 Tatsuya Kumazawa Technical Research & Development Institute, Japan Defence Agency, Japan

Conventionally a fast Fourier transform(FFT) algorithm is applied for digital

beamforming of a sonar system, but this algorithm is inadequate for a sonar system

with large bandwidth since the FFT can not be efficiently performed for wideband

processing. To overcome this disadvantage of the fast Fourier transform algorithm,

wideband processing by the wavelet transform is proposed. In this paper, we study the possibility of the harmonic wavelet transform proposed by Newland for applying to the wideband processing of a sonar system and it can be shown that the sonar signal

processing including beamforming and replica correlation can be replaced by this

wavelet algorithm instead of the FFT algorithm. The simulation for the planar array in a noise environment is also conducted and it is confirmed that this method can improve the signal to noise ratio for wide band signals compared with the conventional FFT method.