next up previous contents
Next: in nepers/m Up: Loss Mechanisms Previous: Loss Mechanisms

Material Absorption

Equations for material absorption in the water column are summarized by Urick[53]. A somewhat standard form due to Thorpe is:

where f is the frequency in kilohertz and is in units of dB/m. Attenuation in sediments is somewhat more complicated and must be specified directly.

Material absorption is included by adding an imaginary part to the sound speed so that . Typically, the attenuation is specified in more physical units so it is necessary to perform a conversion. In the following subsections we present the results for various cases.

Michael B. Porter
Tue Oct 28 13:27:38 PST 1997