ACTIVE SONAR FOR DETECTION OF OBJECTS NEAR BOTTOM, ON BOTTOM AND IN NEAR-SURFACE LAYER OF BOTTOM Russian patent published in 1995 - IPC

FIELD: acoustic detection and ranging systems. SUBSTANCE: device has low-frequency generator and high-frequency generator, receiver, indicator, switch, power amplifier, reception-radiation switch and reversible electroacoustic transducer connected in series, preamplifier whose input is connected to second output of switch, stabilized platform which is mechanically connected with reversible electroacoustic transducer; besides that, device is provided with balanced modulator whose two inputs are connected with generator outputs, low-frequency sound detector to whose output receiver is connected which is connected in its turn with indicator; connected to indicator output are pulse generator and time interval meter to whose output the time-voltage converter and DC amplifier are connected in series; output of DC amplifier is connected with control input of low-frequency generator; device is provided with threshold circuit connected between preamplifier output and second input of time interval meter; pulse generator output is connected with control input of switch. EFFECT: enhanced reliability in detection of semi-submerged and submerged objects, increased detection range, enhanced productivity and reduced consumption of labour required for detection of objects. 3 dwg