Measuring the Vertical Directional Spectra Caused by Sea Surface Sound: A PaperPresented at the Meeting of the Acoustical Society of America (119th), State College, Pennsylvania on 24 May 1990

摘要

The objective of these measurements is the development of a database ofdirectional spectra obtained in an acoustically isolated area (Tongue of the Ocean, The Bahamas) where the acoustic ambient is principally controlled by the local (observable) sea surface conditions. The purpose of the database is the identification of a model of the space-time statistics of sea surface sound. A wideband (40 to 4000 Hz) vertical acoustic linear antenna system was used. Data logging took place in a remote, autonomously operating subsurface buoy system. Recording restrictions limited each of the seven octavely nested apertures of the sensor system to four wavelengths. However, quite adequate spatial resolutions of the directional spectral estimates were obtained using a physically based parametric model of the random process. Results of the initial two-month deployment (wind speed range of 2 to 16 m/s) are discussed. The measured directional spectra are displayed as a function of frequency, elevation angle, and surface friction velocity. The sea surface sound source structure is discussed. Keywords: Underwater acoustics; Ambient noise; Air water interactions; Acoustic data bases. (edc)