Bathymetry Lord Howe 4m GRID

Geoscience Australia carried out a marine survey on Lord Howe Island shelf (NSW) in 2008 (SS062008) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, rock coring, observation of benthic habitats using underwater towed video, and measurement of ocean tides and wavegenerated currents. Subbottom profile data was also collected to map sediment thickness and shelf stratigraphy. Data and samples were acquired using the National Facility Research Vessel Southern Surveyor. Bathymetric data from this survey was merged with other preexisting bathymetric data (including LADS) to generate a grid covering 1034 sq km. As part of a separate Geoscience Australia survey in 2007 (TAN0713), an oceanographic mooring was deployed on the northern edge of Lord Howe Island shelf. The mooring was recovered during the 2008 survey following a 6 month deployment.

lh_4m is an ArcInfo grid of the Lord Howe survey area produced from the processed EM300 bathymetry data of the survey area using the CARIS HIPS and SIPS software.

 
Citation proposal
. Bathymetry Lord Howe 4m GRID. https://dc.niwa.co.nz:/niwa_dc/srv/api/records/f6618a62-9fda-417b-beb9-7acf5a546dc7
 

Simple

Alternate title
lh_4m
Date ( Creation )
2010-10-20
Date ( Revision )
2010-12-20

  Custodian

  +61 2 6249 9920 
Website
http://www.ga.gov.au  

  Publisher

  (02) 6274 1333 
Website
http://www.deh.gov.au  
Presentation form
Digital map
Status
Completed

  Point of contact

  +61 2 6249 9920 
Website
http://www.ga.gov.au  
Maintenance and update frequency
As needed
Name
ArcINFO grid
Version
1
Keywords ( Theme )
  • MARINE Mapping
  • MARINE Geology and Geophysics
Keywords
  • Downloadable Data
Use limitation
subject to agreement
Access constraints
License
Other constraints
This material is released under the Creative Commons Attribution 3.0 Australia Licence.
Spatial representation type
Grid
Distance
4  Meters
Metadata language
English
Character set
UTF8
Topic category
  • Geoscientific information
Environment description
Version 6.2 (Build 9200) ; Esri ArcGIS 10.6.1.9270
N
S
E
W


Reference system identifier
EPSG / UTM55S / 2.1(3.0.1)
Number of dimensions
2
Dimension name
Column
Dimension size
9967
Resolution
4  m
Dimension name
Row
Dimension size
13693
Resolution
4  m
Cell geometry
Area
Transformation parameter availability
true
Checkpoint Availability
false

Center point

Point in Pixel
  • Center
Distribution format
  • SDE Raster Dataset ()

Distributor

  Publisher

  (02) 6274 1333 
Name
ArcInfo grid
Version
1
Hierarchy level
Dataset

Conformance result

Date
Explanation
The positional accuracy is high as required by the multibeam sonar system to properly function
Pass
true
Statement

Due to the 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, WXTide32 software (http://www.wxtide32.com) with reference to the mean sea level and UTC time was used to obtain tidal information, which in turn 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.

Date ( Revision )
2000-01-01

gmd:MD_Metadata

File identifier
f6618a62-9fda-417b-beb9-7acf5a546dc7   XML
Metadata language
English
Character set
UTF8
Hierarchy level
Dataset
Hierarchy level name
dataset
Date stamp
2021-10-18T12:22:15
Metadata standard name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata standard version
2007

  Point of contact

  +61 2 6249 9920 
Website
http://www.ga.gov.au  
 
 

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