HYDROACOUSTIC SYSTEM FOR MONITORING TRAWL PARAMETERS Russian patent published in 2012 - IPC G01S15/96 

FIELD: physics.

SUBSTANCE: apparatus has a surface module 1, lying on a towing vessel, a communication line 2 and an underwater module 3 mounted on the head line of the trawl, which includes a vertical coverage hydroacoustic antenna 4, which is in form of semicircle of a set of receiving-transmitting elements 5, a horizontal coverage hydroacoustic antenna 6, which is in form of at least two horizontal rows of receiving-transmitting elements 7, both hydroacoustic antennae 4 and 6 together with a transmitting-receiving channel are placed inside one sealed housing. The transmitting-receiving channel 3 of the underwater module has mode switching units 8 and 8', multichannel echo amplifiers 9 and 9', analogue-to-digital converters 10 and 10', as well as a unit for switching signals of the communication line 11 and generators of the emitted signals 12 and 12'. The surface module 1 includes a unit for switching signals of the communication line 13, beam pattern formers for hydroacoustic antennae 14 and 14', signal correlation processing units 15 and 15' and square-law detectors 16 and 16' connected to inputs of the unit for processing and displaying the received acoustic information 17.

EFFECT: high efficiency.

3 cl, 1 dwg