FIBER-OPTICAL UNDERWATER LISTENING DEVICE Russian patent published in 1998 - IPC

FIELD: underwater acoustics, detection of location and tracking of underwater targets. SUBSTANCE: several, predominantly, three receivers of gradient of sound pressure oriented by radiation patterns by various coordinates are formed on basis of one fiber-optical interferometer. Receivers of gradient of sound pressure are manufactured in the form of pairs of coils located at specified distance one from another. One of coils of each pair is interference fitted on piezocylinder to which different carrier frequencies are fed. Photodetector of interferometer extracts each carrier frequency with the help of band-pass filters. Demodulators extract legitimate signals fed later into processor that generates information on position of underwater target. EFFECT: enhanced accuracy and reliability. 4 cl, 2 dwg