P. Felisberto and S.M. Jesus pfelis@ualg.pt and sjesus@ualg.pt
SiPLAB-FCT, Universidade do Algarve
8005-139 Faro, Portugal
Comments: download pdf
file .
Ref.: Proc. European Conference on Underwater
Acoustics, ECUA'2006,
(ISBN:), p., Carvoeiro,Portugal, June 2006.
Abstract : Several ocean phenomena, like internal waves or
upwelling, give rise to spatial disturbances of the temperature/sound
speed. The classical methods to found the spatial distribution of these
disturbances is based on in-situ measurements with CTD, XBT, thermistor
chains, etc. These direct methods are generally costly in terms of time
and resources. More recently, methods for remote sensing temperature
disturbances in the ocean by acoustic means, known as acoustic
tomography were introduced. Acoustic tomography is interesting
specially if simple low cost acoustic systems could be used. This work,
starting from such an acoustic system, proposes a method for estimating
the distribution of temperature/sound speed disturbances in the ocean
and its uncertainty. The proposed method is based on a two step
procedure. Firstly, a matched field technique is used to estimate the
"mean" sound speed disturbances between sound sources and receivers. In
the second step, a spatial distribution of the sound speed disturbances
is found using a ray tracing method. The method also allows to include
in-situ measurements in the estimation, reducing the uncertainty. The
applicability of the method is demonstrated by simulations based on
real data from the INTIMATE'98 sea trials.
ACKNOWLEDGMENT: this work was partially supported by FCT project ATOMS -POCTI/P/MAR/15296/1999.