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Vertical array receptions of the Heard Island transmissions

Journal Article · · Journal of the Acoustical Society of America; (United States)
DOI:https://doi.org/10.1121/1.410112· OSTI ID:7007954
;  [1];  [2]; ;  [3];  [4];  [5]
  1. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  2. Monterey Bay Aquarium Research Institute, Monterey, California 93943 (United States)
  3. Naval Postgraduate School, Monterey, California 93943 (United States)
  4. Science Applications International Corporation, McLean, Virginia 22102 (United States)
  5. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 (United States)

A long, vertical line array was deployed off Monterey, California during the Heard Island Feasibility Test to measure the modal content of the received signals. The array contained 32, equally spaced hydrophones spanning from 345 to 1740-m depth. The multichannel data were recorded through a tether to the R/V POINT SUR. The measurements had very low signal to noise ratios and indicated the cw transmission losses were approximately 140 dB for a source/receiver range of 17 000 km. Modal content was analyzed using (i) the modal extent versus depth, (ii) frequency-vertical wave-number spectra, (iii) modal beamforming and (iv) least squares fitting. All led to the conclusion that the modal population is surprisingly rich. There was strong evidence of population up to at least mode seven in the data.

OSTI ID:
7007954
Journal Information:
Journal of the Acoustical Society of America; (United States), Journal Name: Journal of the Acoustical Society of America; (United States) Vol. 96:4; ISSN 0001-4966; ISSN JASMAN
Country of Publication:
United States
Language:
English