Tasmania – Tasman Peninsula, Freycinet MPA and Governor’s Island (Barrett, Johnson):Dives in Tasmania were focused on two main goals. One aspect of the surveys in Tasmania is to look at deepwater benthic assemblages associated with rocky reefs. These dives featured broad grids over the dive sites and a pair of dense overlapping grids. Around the Tasman peninsula, dives were completed in shallower water and featured a pair of dense grids connected by reciprocal legs. Two sites near the Nuggets and in the Freycinet MPA were revisited from previous trips in 2008 and 2009. These were broad grids and did not feature any dense grids making direct comparison difficult.
Maintenance and Update Frequency: asNeeded
Statement: This data is provided by the IMOS AUV Facility and was collected by the University of Sydney's Australian Centre for Field Robotics aboard the TAFI Research Vessel R/V Challenger. The AUV Sirius undertook seafloor survey deployments along the Tasmanian Peninsula, at Port Arthur and in the Huon Channel between October 5th and 16th, 2008. This
represents a first pass processing completed while onboard the ship. A more thorough revision may be available in the future.
In all 19 dives were completed, in addition to a number of calibration dives which are not contained on this disk. Each mission has been processed to generate a dive report, dive tracks, geotifs and meshes. Multibeam and hydrographic data have been completed for some but not all dives. The structure of each dive summary is as follows:
.pdf - a report outlining the dive. This shows some dive stats (date, time, depth, number of images, distance travelled, etc.), the raw mission profile, a depth profile, the hydrographic data and the reprocessed navigation data where available.
.kml - this is a kml file of the vehicle path that can be loaded into Google Earth.
_latlong.csv - this is comma separated value file containing a summary of the imagery collected by the vehicle during the dive. This is a result of the output of the renavigation and should be self-consistent where loop closures were identified. USBL and GPS observations have also been fused into the navigation filter. The csv file
contains data for each image including the date and time, local northing and easting in metres, depth, latitude and longitude, roll, pitch, heading, altitude and the names of the two stereo images.
hydro/ct.csv - a csv containing the conductivity and temperature measurements taken during the dive. These include the date and time, interpolated northing and easting, depth, latitude and longitude, conductivity, temperature measurements and salinity, pressure and speed of sound.
hydro/eco.csv - a csv containing the ecopuck fluorometer measurements. These include the date and time, interpolated northing and easting, depth, latitude and longitude, chlorophyll-a, backscatter (red), cdom and temperature (note that this particular sensor does not measure temperature and this field is filled with a dummy value).
i_gtif - this directory contains geotiffs of the left, colour images collected during the dive. These contain georeferencing tags generated by the navigation. If loaded into a GIS they should be displayed at the correct geographic location. The image footprint accounts for the field of
view of the camera and the measured altitude of the vehicle, The encoding within each image is PNG and should be viewable in a standard image viewer.
mb - this directory contains GRD files of the multibeam data, intensities and associated variances.
mesh - this directory contains a mesh of the data based on the navigation and the stereo reconstructions. These can be viewed using the osgsight utility by loading the final.ive file. The mesh will show the local stereo surface with associated texture maps.
Australia’s Integrated Marine Observing System (IMOS) is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent.
Australian Centre for Field Robotics (ACFR)
Commonwealth Environmental Research Facility (CERF) Marine Biodiversity Research Hub