Bathymetry grid of Darwin Harbour from Survey onboard the Matthew Flinders - 2011

Note: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2.

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Dataset citation

ANZLIC unique identifier: ANZCW0703016635

Title: Bathymetry grid of Darwin Harbour from Survey onboard the Matthew Flinders - 2011

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Custodian

Custodian: Geoscience Australia

Jurisdiction: Australia

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A bathymetric survey of Darwin Harbour was undertaken during the period 24 June to 20 August 2011 by iXSurvey Australia Pty Ltd for the Department of Natural Resources, Environment, The Arts and Sport (NRETAS) in collaboration with Geoscience Australia (GA), the Darwin Port Corporation (DPC) and the Australian Institute of Marine Science (AIMS) using GA's Kongsberg EM3002D multibeam sonar system and DPC's vessel Matthew Flinders.

ANZLIC search words:

GEOSCIENCES Mapping
MARINE
MARINE Geology and Geophysics Mapping

Spatial domain:

locality map

Geographic extent name: AUSTRALIA EXCLUDING EXTERNAL TERRITORIES - AUS - Australia - Australia

Geographic extent polygon: 130.69 -12.32, 130.94 -12.32, 130.94 -12.59, 130.69 -12.59, 130.69 -12.32,

Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register

Geographic bounding box:: North bounding latitude: -12.32 °; South bounding latitude: -12.59 °; East bounding longitude: 130.94 °; West bounding longitude: 130.69 °

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Data currency

Beginning date: 2011-06-24

Ending date: 2011-08-20

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Dataset status

Progress: Complete

Maintenance and update frequency: Not Known

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Access

Stored data format:: DIGITAL - seg y Seismic digital data - SEG Y format Universal Transverse Mercator (UTM) WGS84

Available format type:: DIGITAL - seg y Seismic digital data - SEG Y format Universal Transverse Mercator (UTM) WGS84

Access constraints:

This material is released under the Creative Commons Attribution 3.0

Free Data Download

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Data quality

Lineage:

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 7.1. 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, The observed tide with reference to the mean sea level and UTC time 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. The processed data was finally exported as XYZ grid soundings and converted into ArcINFO grid as well as geotiff and Caris csar file.

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

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