M. Palmese, A.Bozzo demarinis@dune-sistemi.com
DIBE, Universita di Genova, Genova, Italy
S.M. Jesus sjesus@ualg.pt
SiPLAB-FCT, Universidade do Algarve
Faro, Portugal
J. Onofre mesquita.onofre@hidrografico.pt
Instituto Hidrografico, Lisboa Portugal
P. Picco picco@santa-teresa.enea.it
ENEA, La Spezia, Italy
A. Trucco
DIBE, Universita di Genova, Genova, Italy
Comments: download pdf file .
Ref.: Proc. ECUA 2002, (ISBN 83-907591-8-7),
p.755-760, Gdansk (Poland), June 2002.
Abstract : In this paper, acoustic data collected in shallow water
during INTIMATE00 sea trials are analysed with the aim to detect
fluctuations in acoustical signals under the effect of a time−varying
environment. Some time−frequency analysis methods, i.e., Gabor
Expansion and Wigner−Ville Distribution, have resulted to be adequate
to find out fluctuations in the received signals, in particular, such
analyses reported different time−frequency behaviour in relation with
different tidal conditions. The variations observed in the received
acoustic data have been compared with the temperature data collected
during the sea trials and the related sound−speed profiles: it has been
reported that major signals fluctuations over time in the acoustic
signal occur in correspondence of the sound−speed profile changes
linked to environmental variability.
ACKNOWLEDGMENT: this work was partially supported by projects TOMPACO (CNR, Italy), INTIMATE and ATOMS from FCT (Portugal).