Ray Representation of Sound Scattering by Weakly Scattering Deformed Fluid Cylinders; Simple Physics and Application to Zooplankton.
WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
Pagination or Media Count:
Data indicate that certain important types of marine organisms behave acoustically like weakly scattering fluid bodies i.e., their material properties appear fluidlike and similar to those of the surrounding fluid medium. Use of this boundary condition, along with certain assumptions, allows reduction of what is a very complex scattering problem to a relatively simple, approximate ray-based solution. Because of the diversity of this problem, the formulation is presented in two articles this first one in which the basic physics of the scattering process is described where the incident sound wave is nearly normally incident upon a single target i.e., the region in which the scattering amplitude is typically at or near a maximum value for the individual and the second one Stanton et at., J. Acoust. Soc. Am. 94, 3463-3472 1993 where the formulation is heuristically extended to all angles of incidence and then statistically averaged over a range of angles and target sizes to produce a collective echo involving an aggregation of randomly oriented different sized scatterers.