Inventors:
Jirair A. Babikyan - Woburn MA
Assignee:
Sanders Associates, Inc. - Nashua NH
International Classification:
H04R 1100
Abstract:
A directional hydrophone comprises a plurality of coil elements each disposed in an air gap in a common magnetic circuit. In a first embodiment of the invention two coil elements each have a single degree of freedom of motion which is orthogonal to the other. The force due to an acoustic wave impingent upon the hydrophone is resolved into two orthogonal components by the two coils which give rise to two distinct electrical output signals proportional to the sine and cosine respectively of the angle at which the acoustic wave arrives. In another embodiment of the invention each coil element has two degrees of freedom of motion and the movement of each of the coil elements is resolved into two orthogonal components by the effective length of the coil which varies in a known manner with the angle of coil motion with respect to the polarity of the magnetic circuit.