Improvements in or relating to heading control in sonic direction-finding systems

摘要

942,490. Sound direction-finding. MINISTER OF NATIONAL DEFENCE OF H.M. CANADIAN GOVERNMENT. April 14, 1961 [Aug. 31, 1960], No. 13564/61. Heading H4D. In a system whereby the direction and distance of submarine objects is electronically determined, and in which a directional electroacoustic transducer 10, Fig. 2, is positioned in a body 11 towed behind a vessel, apparatus for controlling the heading of the transducer comprises a compass 14 fixed to body 11 and producing an output B BN corresponding to the body's heading, means coupled to the transducer to signal the bearing B TB of the transducer relative to the body's axis, means 16 mounted in the body and coupled to the B BN and B TB outputs to provide an output B TN representing the transducer heading relative to true north, and means 18 adapted to compare the output B TN and a desired transducer heading and to provide a difference-signal output which, by drive means 13 mounted in body 11, rotates the transducer until the difference-signal output is zero. The behaviour of the towed body, e.g. due to wind and tide, is thereby compensated. More details of the embodiment illustrated schematically by Fig. 2 are described, Fig. 3 (not shown). Noise to the transducer from the compass is absorbed by air, lead, or rubber baffles.