Loading...
Publication
Ocean parameter estimation with high-frequency signals using a vector sensor array
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 8.07 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Vector sensors began to emerge in 1980s as potential competitors to omni
directional pressure driven hydrophones, while their practical usage in underwater
applications started in the last two decades. The crucial advantage
of vector sensors relative to hydrophones is that they are able to record both
the omni-directional pressure and the three vectorial components of the particle
velocity. A claimed advantage of vector sensors over hydrophones is
the quantity of information obtained from a single point spatial device,
which potentially allows for high performance small aperture Vector Sensor
Arrays (VSA). The capabilities of such small aperture VSA have captured
the attention for their usage in high-frequency applications. The main contribution
of this work is the understanding of the gain provided by vector
sensors over hydrophones whenever ocean environmental parameter estimation
is concerned. In a rst step a particle velocity-pressure joint data model
is proposed and an extended VSA-based Bartlett estimator is derived. This
data model and estimator, initially developed for estimating direction of
arrival, are generalized for ocean parameter estimation, assuming a particle
velocity capable physical model - the TRACEO model. The highlighted capabilities
of the VSA are rst demonstrated for angle of arrival estimation,
where a variety of spatial con gurations of hydrophone arrays are compared
to that of a vertical VSA. A vertical VSA array con guration is then
used for estimating geoacoustic bottom properties from short range acoustic
data, using two VSA-based techniques: the generalized Bartlett estimator
and the re
ection coe cient estimator proposed by Harrison et al.. The
proposed techniques where tested on experimental VSA data recorded in
shallow water area o the Island of Kauai (Hawaii) during the MakaiEx
2005 experiment. The obtained results are comparable between techniques
and inline with the expected values for that region. These results suggest
that it is indeed possible to obtain reliable seabed geoacoustic properties'
estimates in a frequency band of 8-14 kHz using a small aperture VSA with
only a few sensors.
Description
Tese de dout., Engenharia Electrónica e Telecomunicações (Processamento de Sinal), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2012