A hydroacoustic system that radiates at frequencies of 19−26 Hz

Supersensitive Detector of Hydrosphere Pressure Variations

“…From left to right: harmonic signal with a duration of 30 s, phase-shift keyed signal (M-sequence) with a duration of 30 s, phase-shift keyed signal (M-sequence) with a duration of 10 s, sweep signal with a duration of 10 s, two phase-shift keyed signal (M-sequence) with a duration of 15 s. In the summer of 2019, we researched the regularities of low-frequency hydroacoustic signals propagation from the open sea to a semi-closed bay through the land part of Shultz Cape. Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”

“…Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”

“…The developed and created supersensitive detector of hydrosphere pressure variations based on an equal-arm Michelson interferometer, which has unique amplitude-frequency characteristics, is designed In the summer of 2019, we researched the regularities of low-frequency hydroacoustic signals propagation from the open sea to a semi-closed bay through the land part of Shultz Cape. Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”

Study of Low-Frequency Hydroacoustic Waves’ Behavior at the Shelf of Decreasing Depth

“…The map of the experiment is shown in Figure 1. The research vessel was anchored at the "radiation point" (coordinates N 42 • 35.6827 , E 131 • 09.8707 ) at a depth of 32 m. From its board, a low-frequency hydroacoustic transmitter of the electromagnetic type was immersed to a depth of 18 m [4], generating in the water harmonic signals at a frequency of 22 Hz.…”

An Autonomous Low-Frequency Broadband Hydroacoustic Emitting Station

“…В качестве электроакустического преобразователя, исходя из требований к срокам автономности, массогабаритным характеристикам и излучаемой акустической мощности станции, был выбран преобразователь электромагнитного типа. Электромагнитные преобразователи в данном частотном диапазоне обладают рядом преимуществ: они просты в изготовлении и обслуживании, обладают наиболее высокими удельной мощностью и электроакустическим КПД по сравнению с пьезоэлектрическими и электродинамическими преобразователями [2]. Кроме того, для задач подводного позиционирования и ретрансляции гидроакустических сигналов, а также обработки и интерпретации, полученных в океанологических исследованиях, натурных данных, существует необходимость в наличии канала синхронизации с различными устройствами и регистрации гидроакустических сигналов.…”