| 摘要 |
PURPOSE:To make it possible to take out only the signal from a target by avoiding sea-surface or sea-bottom reverberation, by detecting the depth of water and pitch angle of an active sonar apparatus and changing the frequency of a transmission signal corresponding to a detection signal. CONSTITUTION:The pitch angle of a sonar apparatus is detected by a pitch angle sensor 9 and the depth of said apparatus is detected by a depth sensor 8 and detection signals are applied to a transmission frequency controller 4 and a receiving frequency controller 1. Both controllers 4, 7 receive the control of the frequencies thereof so as to narrow the width of sonic beam emitted from a transmitter receiver 1 as the pitch angle becomes larger or the depth becomes shallower. Therefore, sea-surface or sea-bottom reverberation is hard to contain in the signal received by a receiver 5. |
