narrowband sounder
1Sonar — This article is about underwater sound propagation. For atmospheric sounding, see SODAR. For other uses, see Sonar (disambiguation) …
2Underwater acoustics — The field of underwater acoustics is closely related to a number of other fields of acoustic study, including sonar, transduction, acoustic signal processing, acoustical oceanography, bioacoustics, and physical acoustics.HistoryUnderwater sound… …
