Horizontal directional spectrum estimation of the Heard Island transmissions

In 1991 the Heard Island Feasibility Test demonstrated that it is possible to transmit coded acoustic signals nearly half way around the world. One of the key issues in the feasibility test was to determine the spatial structure of the received transmissions. In this thesis, data from the Canadian Defense Research Establishment Pacific horizontal line array is used to form an estimate of the directional power spectrum. This spectrum determines if any horizontal multipath is detectable. The preliminary signal conditioning, including frequency spectrum estimation and demodulation required before beamforming is described. Conventional and adaptive beamforming methods are examined with synthetic data to demonstrate the limitations on the directional spectrum results. The principle result of this work is that no stable horizontal multipath is evident. The mean arrival angle for the five hours of data analyzed is 212° ± 1.5°.

Grantor dc:publisher

Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

Year dc:date.issued

1994

Author dc:creator

• Traykovski, Peter A.

• Signal processing
• Sound
• Hearing
• Underwater acoustics

Language dc:language.iso

en_US

DOI

10.1575/1912/5549

OAI identifier oai:identifier

oai:darchive.mblwhoilibrary.org:1912/5549