FIELD: hydroacoustics. SUBSTANCE: high-frequency pumping signal is radiated at n-frequencies (n=2, 3, 4, etc.) into nonlinear water medium in direction of sea bottom. This is done with the aid of n-radiators positioned in definite way on ship hull. Radiators are oriented in definite way relative to source of low-frequency signals. High-frequency pumping signal is scattered by sea bottom. Being modulated in amplitude by useful low-frequency signal, high-frequency pumping signal is received by means of n-receivers arranged on ship hull in definite order. Low-frequency signal is separated from combination frequency signal by amplitude demodulation method. This is performed in multichannel (n channels) signal processing unit. Formation and scanning of directivity characteristics in preset plane is carried out by means of compensator. Quantitative and qualitative characteristics of source of low-frequency hydroacoustic radiation are judged by spectral analysis of signals and by comparison of received signal with standard one. EFFECT: more effective detection of hydroacoustic radiations. 4 dwg
