Rep 04/03 - SiPLAB
10/Nov/2003Environmental inversion of acoustic signals for bottom and water column properties is
being proposed in the literature as an interesting concept for complementing direct hydrographic
and oceanographic measurements for Rapid Environmental Assessment (REA).
The acoustic contribution to REA can be cast as the result of the inversion of ocean
acoustic properties to be assimilated into ocean circulation models specifically tailored
and calibrated to the scale of the area under observation. Traditional ocean tomography
systems and methods for their requirements of long and well populated receiving
arrays and precise knowledge of the source/receiver geometries are not well adapted to
operational Acoustic REA (AREA).
An innovative concept that responds to the operational requirements of AREA is being
proposed under a Saclantcen JRP jointly submitted by the the Universit´e Libre de
Bruxelles (ULB), SiPLAB/CINTAL at University of Algarve, the Instituto Hidrogr´afico
(IH) and the Royal Netherlands Naval College (RNLNC) and approved by Saclantcen
in 2003 under the 2004 SPOW. That concept includes the development of water column
and geo-acoustic inversion methods being able to retrieve environmental true properties
from signals received on a drifting network of Acoustic-Oceanographic Buoys (AOB). A
prototype of an AOB and a preliminary version of the inversion code, was tested at sea
during the Maritime Rapid Environment Assessment’2003 sea trial (MREA’03) and is
described in this report together with the results obtained.This report presents the AOB system and the results obtained during its testing in the
MREA’03 sea trial. The MREA’03 sea trial took place off the Italian coast, near Elba I.
in the period 26 May - 27 June 2003.
The authors of this report would like to thank: the SACLANT Undersea Research Centre for the opportunity for participating in
the sea trial
• the scientist in charge Dr. Emanuel Coelho; the collaboration of Saclantcen personnel; the master and crew of the R/V Alliance; the contribution of Prof. J.-P. Hermand from ULB for the discussions and pictures
shown in this report
