Operational Models for Acoustic Scattering by Marine Organisms


Kenneth J. Foote, Applied Ocean Physics and Engineering

Grant Funded 2007

Sonar is being used all over the world in investigations of marine organisms. To aid in the interpretation of sonar echo signals, it is useful to be able to refer to prior data or to algorithms that predict the echo responses from marine organisms. In many instances, such data and predictions are incorporated in so-called acoustical scattering models.  Notwithstanding the recognized usefulness of such models and their widespread use, each use is essentially characterized by an independent implementation. In addition, there are few standards available for checking the results of these implementations.

It is the goal of this proposal to implement a number of acoustic scattering models in an interactive online visualization application. The availability of these models to the general user over the Internet will enable several technical quantities to be computed on an interactive basis. These will include the resonance frequency of gas inclusions; the mean backscattering cross section and target strength of surface-adapted clupeoids, e.g., herring, and gadoids, e.g., cod; and the backscattering cross section and target strength of representative euphausiids, copepods, pteropods, and siphonophores.

The user will be able to select organism types from a menu, specify dimensions of interest, e.g., organism length or mass, obtain plots of resulting computations, and export computational results in an ASCII file.

The same application will also incorporate selectable examples from the literature, thus fulfilling a benchmarking function. This will enable individual user-implementation of models to be verified.