The Arctic Channel: An Acoustic Waveguide.

• Main Author: DiNapoli,F R
• Other Authors: NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT NEW LONDON LAB
• Format: Text
• Language: English
• Published: 1978
• Subjects: Physical and Dynamic Oceanography; Numerical Mathematics; Acoustics; *Acoustic channels; *Arctic Ocean; *Sound transmission; Frequency modulation; Sea ice; Acoustic velocity; Very low frequency; Long range(Distance); Pulse compression; Matched filters; Waveguides; Mathematical prediction; Fast fourier transforms; Wave propagation; Ocean basins; Ice cover; PE62759N; WU19325; LPN-NUSC-A65002; Arctic; Arctic Ocean; Arctic Basin
• Online Access: http://www.dtic.mil/docs/citations/ADA131678; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA131678

The Arctic Basin provides a unique channel for acoustic propagation. The two features peculiar to the polar environment that most strongly influence the transmission of underwater sound are the permanent ice cover and the uniform sound speed structure. As a result, only a few low order modes will propagate through it to great distances and the non-linear frequency dependent time delay of the channel may be accurately computed. In the Arctic channel, the disperson is such as to prodce a 'chirp' frequency modulation on a transmitted pulse. Consequently the channel itself may be used as the matched receiving filter by transmitting a time reversed (chirped) waveform and letting the dispersion effect compress the waveform. This process will be strictly range dependent. (Author) Presented at Underwater Acoustics Group of the Institute of Acoustics Meetings on: Sound Propagation and Underwater Systems, London, 10-11 Apr 78.