| 摘要 |
PURPOSE:To prevent evil influence of internal noise of a sonar by making the acoustic velocity of a medium in the dome of the sonar, having a sound insulating plate for internal noise behind a signal detector faster than that of sea water. CONSTITUTION:In a dome 1, a signal detector 2 is installed and a medium 6 is charged; and a sound insulating plate 4 for internal noise is fitted behind the signal detector 2. The medium 6 has a higher acoustic velocity than sea water as a medium 7 outside the dome 1. For this purpose, there are three kinds of method-using a medium having a higher acoustic medium, increasing the pressure of the medium, and raising the temperature of the medium. Consequently, the angle of refraction of the internal noise is increased and total reflection on the boundary surface of the medium is realized; and the quantity of a refracted and a diffracted wave entering the dome is reduced to reduce the influence of internal noise of a sonar. |
