Sound speed and attenuation measurements of sandy sediments in reverberation chamber

Abstract

Sound speed and attenuation in sandy sediments are important acoustic parameters. But the uncertainties of current in-situ measurements at low-frequency are very large and the data are not sufficient to be used to test theory predictions. As an alternative, measurements in a water filled isolated reverberation chamber were attempted in laboratory, which preserves lower frequency limitation and smaller scale requirement of water tank. In order to know the feasibility of the method, a type of fine sand sediments was measured. Spatial averaged reflection and transmission coefficients of the sand layer and attenuation were calculated over the frequency range of 90–170 kHz. And sound speed was inverted with these measured parameters. After then measurements at low-frequency till to 2 kHz were tried in the same tank.