ANGULAR LOCALISATION IN DOLPHIN HEARING DERIVED FROM TRANSMISSION LINE MATRIX MODELLING OF THE LOWER JAW AND TEETH.

摘要

Dolphin echolocation, like any sonar, is a system consisting of many components, but essentially a transmitter, a receiver and a processor. This paper is mainly concerned with the receiving mechanism, along with the processing involved in beam forming and target localization. A wider discussion of dolphin echolocation and hearing will be found in the book by Au [1] or a more recent collection of articles covering all aspects of echolocation [2]. There is evidence that the dolphin's lower jaw is a component in the echolocation receiver, and Goodson and Klinowska [3] have proposed a model suggesting the equally spaced rows of teeth form receiving arrays. Various processing schemes for these 'tooth arrays' have been suggested (e.g. [4]) but, whatever the details, such arrays in an end-fire mode, unlike broadside arrays, should maintain directivity in the near field [5]. In addition, combining the rows of teeth in a monopulse configuration would give fine angular resolution but with wide beams for rapid area searching [6,7].