Comments: download file (cintal_rep)
Ref.: SiPLAB Report 03/07, FCT, University of Algarve,2007.
Abstract
Among the existing panoply of instrumentation for Rapid Environmental Assessment (REA),
underwater unmanned vehicles, satellite remote sensing and oceanographic drifters attract
particular attention. In the last years, there has been a growing interest in coupling
purely oceanographic surveys and acoustic measurements, in order to provide a final
environmental image that is not only oceanographically consistent but also acoustically
coherent for the area and period of interest. Thus, the usage of remote acoustic equipment
is becoming an integrand part of the REA equipment list. One of the major characteristics
of REA equipment is its unique capability for remote, often unsupervised, operation and
compactness. The Acoustic Oceanographic Buoy Joint Research Project (AOB-JRP) was launched
in 2004 with the objective of develop and test at sea a dedicated sensing device for
acoustic REA (AREA). The MREA/BP'07 sea trial was designed to assess the joint capabilities
of both oceanographic remote sensing and acoustic means to attain a recognizable picture
of the environment in a particular location at a given time, able to provide suitable short
term sonar predictions. A series of environmental measurements, ocean circulation modelling
and acoustic probing were performed in order to both obtain a suitable data base for validation
purposes and simultaneously provide an operationally realistic sampling strategy. Environmental
measurements included extensive CTD and MVP casts over the BP03 and adjacent areas and from NRV
Leonardo during acoustic transmissions, bottom grab samples in the shallower area (below 50 m
depth), Uniboom and X-Star profiling along the whole BP03 area, multibeam surveys along the
main propagation paths (both with HmSr Snellius and the Remus vehicles), thermistor strings
at points A, B and incorporated in the AOB drifting arrays and finally a Waverider buoy in
the middle of the BP03 area. Acoustic measurements took place from the HmSr Snellius RHIB
or Sloop using a set of sparse arrays and/or from the free drifting AOB's, receiving
pre-coded sequences transmitted from NRV Leonardo sound source or using occasional sources
of opportunity. This report describes in detail the AOB data set and a few associated
environmental measurements available at the time of publication. Other data sets will be
described in companion reports or posted in the NURC Geos website by the responsible
institutions.
ACKNOWLEDGMENT: SiPLAB participation in this sea trial was financed by ULB. Equipment
was partially supported by project RADAR (POCTI/CTA/47719/2002) from FCT, Portugal.