FIBER-OPTICAL DIRECTION FINDER OF UNDERWATER SOUND BEACON Russian patent published in 2004 - IPC

FIELD: underwater acoustics. SUBSTANCE: invention can be utilized by underwater swimmers to determine bearing to underwater sound beacon in sea environment. Salient feature on invention lies in positioning of two fiber-optical coils at certain distance, in their matching with source of coherent light and photodetector of interferometer. Plane acoustic wave from underwater sound beacon arrives simultaneously at both coils only if its front is parallel to measurement base. In this case zero phase difference is observed across output of interferometer, so then zero output signal is recorded by pointer-type null detector and in headphone of underwater swimmer. When underwater swimmer deviates from preset bearing signal the greater the larger given deviation is appears across output of direction finder. EFFECT: simplified design of direction finder, expanded field of application of direction finder due to potential for reception of any signals emitted by underwater sound beacon. 3 dwg