Publication Date:
2022-05-25
Description:
Submitted in partial fulfillment of the requirements for the degree of Ocean Engineer at the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution January 1994
Description:
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°.
Description:
The Office of Naval Research provided funding
for the author under the ONR fellowship program.
Keywords:
Signal processing
;
Sound
;
Hearing
;
Underwater acoustics
Repository Name:
Woods Hole Open Access Server
Type:
Thesis
Format:
application/pdf
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