FIELD: underwater acoustic facilities carrying parametric receiving antennas used in search for fish. SUBSTANCE: device has generator, power amplifier, radiator of high-frequency pumping signal connected to receiving antenna whose output is linked to input of preamplifier which output is linked to input of unit for nonlinear processing of signals that includes band-pass filter of ultrasonic frequencies whose central frequency corresponds to that of high-frequency pumping signal. Amplitude detector, low- frequency filter and low-frequency amplifier, band-pass filter of infrasonic and low acoustic frequencies and band-pass filter of acoustic frequencies are connected in parallel one to another to output of low-frequency amplifier which is output of unit for nonlinear processing of signals. Output of band-pass filter of infrasonic and low acoustic frequencies is connected to first input of adder and output of band-pass filter of acoustic frequencies is frequently linked to first input of correlator. Second band- pass filter of acoustic frequencies is input of unit for nonlinear processing of signals. This filter is connected with its input to output of preamplifier in parallel to input of band-pass filter of ultrasonic frequencies. Amplifier of acoustic frequency range and integrator are connected in series to output of second band-pass filter of acoustic frequencies. Output of integrator is in this case output of unit for nonlinear processing of signals and is connected to second input of correlator. Output of correlator is connected to second input of adder and output of the latter is connected to input of spectrum analyzer. Device is fitted with fixtures for antenna scanning in horizontal and vertical planes. EFFECT: enhanced noise immunity and expanded frequency range of received signals. 5 dwg, 1 tbl
