摘要 |
PURPOSE:To obtain a precise measured value even when the S/N of underwater sound is low by installing directional receivers which have a cosine and a sine pattern at the acoustic center position of receiver arrays at right angles and in parallel to the array axis. CONSTITUTION:The dipole directional receiver 22 having the cosine pattern, the dipole directional receiver 23 having the sine pattern, and a compass 24 are installed at the acoustic center position of the receiver array, i.e. the position of a omnidirectional receiver 9 to measure an azimuth. Namely, acoustic signals of omnidirectional receivers 1-17 and the dipole directional receivers 22 and 23 and the signal of the compass 24 are collected and multiplexed by a terminating circuit 20, and sent out through a cable 21. An observation station demultiplexes and demodulates the multiple signal, and adjusts the phases of receive signals of the omnidirectional receivers 1-17 to generate and listen to a beam; and the beam output which can be listened to with the best S/N and the signals of the dipole directional receivers 22 and 23 are used to calculate the azimuth. |