|
|
|
You are here: Home > GA Metadata
|
||||
|
GA Metadata Related Links |
Bathymetry grid of the Freycinet Peninsula survey areaNote: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2. Dataset citationANZLIC unique identifier: ANZCW0703015276 Title: Bathymetry grid of the Freycinet Peninsula survey area CustodianCustodian: Geoscience Australia Jurisdiction: Australia DescriptionAbstract: Geoscience Australia carried out marine surveys in southeast Tasmania in 2008 and 2009 (GA0315) to map seabed bathymetry and characterise benthic environments through observation of habitats using underwater towed video. Data was acquired using the Tasmania Aquaculture and Fisheries Institute (TAFI) Research Vessel Challenger. Bathymetric mapping was undertaken in seven survey areas, including: Freycinet Pensinula (83 sq km, east coast and shelf); Tasman Peninsula (117 sq km, east coast and shelf); Port Arthur and adjacent open coast (17 sq km); The Friars (41 sq km, south of Bruny Island); lower Huon River estuary (39 sq km); D Entrecastreaux Channel (7 sq km, at Tinderbox north of Bruny Island), and; Maria Island (3 sq km, western side). Video characterisations of the seabed concentrated on areas of bedrock reef and adjacent seabed in all mapped areas, except for D Entrecastreaux Channel and Maria Island. freycinet_160 is an ArcINFO grid of the Freycinet Peninsula survey area produced from the processed EM3002 bathymetry data using the CARIS HIPS and SIPS software. ANZLIC search words:
Spatial domain:
Geographic extent name: AUSTRALIA EXCLUDING EXTERNAL TERRITORIES - AUS - Australia - Australia Geographic extent polygon: 147 -42, 148.55 -42, 148.55 -43.6, 147 -43.6, 147 -42, Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register
Data currencyBeginning date: 2010-10-20 Ending date: 2010-10-20 Dataset statusProgress: Complete Maintenance and update frequency: Not Known Access
Access constraints: This material is released under the Creative Commons Attribution 3.0 Australia Licence. Free Data DownloadData qualityLineage: Due to the exceptionally good quality data being acquired, post processing of the raw data was kept to a minimum. Swath data was processed through Caris HIPS/SIPS version 7.2. First a vessel configuration file was created that the coordinates of the motion sensor and DGPS antenna and patch test offsets were recorded. A new project was then created and the vessel configuration file was attached to the project file. The raw swath sonar data, in raw.all format, for each line was then imported into the project and the vessel information assigned to the data. The motion sensor, DGPS and heading data were then cleaned using a filter that averaged adjacent data to remove artifacts. Different sound velocity profiles data for each block were attached to the corresponding raw swath sonar data files to correct the depths for changes in the speed of sound through the water column. Then a new blank field area was defined that specified the geographic area of study and the coordinate system used. The coordinates for all the study areas were WGS84. The data was cleaned by applying several filters that removed any remaining spikes in the bathymetry data using user defined threshold values. A visual inspection of the data for each line was then undertaken where artefacts and noisy data not removed by the filtering process were removed manually using Swath and subset editors modules of the Caris HIPS/SIPS software. In addition, GPS tidal information was used to correct for the tidal variations in the processing. All the data for each bathymetric, motion sensor, DGPS, heading, tide and sound velocity profile data were merged to produce the final processed data file. A weighted grid of the processed data was then created for each Block. The processed data was finally exported as XYZ grid soundings and converted into ArcINFO grid. Positional accuracy: Inherited from raw data in which C-NAV system was used to provide geographical postion with a manufacturer accuracy of 10 cm RMS. Inherited from raw data in which Applanix system was used to provide roll and pitch, and heave with manufacturer accuracies for roll and pitch are 0.05 deg. RMS, and manufacturer accuracy for heave is 5 cm. Attribute accuracy: The accuracy is high but it is cell size dependent. Note that the water depth dictates the cell size Logical Consistency: All procedures, steps and software involved in producing a bathymetry grid are similar Completeness: Completed Contact information
Metadata informationMetadata date: 2013-03-08 Additional metadataMetadata reference XHTML: http://www.ga.gov.au/meta/ANZCW0703015276.html Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703015276.xml . Authors:Geoscience Australia |
|||
|
SPATIAL INFORMATION FOR THE NATION
|