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A bathymetric Digital Elevation Model (DEM) of Brown Bay, Windmill Islands

Entry ID: brownbay_bathy_dem

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Summary

Abstract: This dataset is a Digital Elevation Model (DEM) of Brown Bay, Windmill Islands and contours and bathymetric contours derived from the DEM.

The data are stored in a UTM zone 49 projection.

They were created by interpolation of point data using Kriging.

The input point data comprised soundings and terrestrial contour vertices.

THE DATA ARE NOT FOR NAVIGATION PURPOSES.

Related URL

Link: GET DATA

Description: Access to data and documentation files via a registered zip file containing 3 folders and a readme file explaining what is in each folder: 1.input data (training and test data) 2.DEM data 3.documentation about the method and validation

Link: VIEW RELATED INFORMATION

Description: Citation reference for this metadata record and dataset

Geographic Coverage

(Click for Interactive Map)

Spatial coordinates

	N: -66.28	S: -66.28	E: 110.55	W: 110.54
Min Altitude: 0 M Max Altitude: 12 M
Min Depth: 0 M Max Depth: 16 M

Temporal Coverage

Start Date: 1997-02-01

Stop Date: 1997-03-31

Start Date: 2000-02-05

Stop Date: 2000-02-05

Location Keywords

OCEAN > SOUTHERN OCEAN

CONTINENT > ANTARCTICA > Windmill Islands

GEOGRAPHIC REGION > POLAR

Science Keywords

LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION

OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY

ISO Topic Category

ELEVATION

IMAGERY/BASE MAPS/EARTH COVER

Platform

DEM > Digital Elevation Model

GPS > Global Positioning System Satellites

Instrument

GPS > Global Positioning System

GPS RECEIVERS

ECHO SOUNDERS

Quality The point data brown_1.txt, brown_2.txt, brown_3.txt and brown_4.txt described by the metadata record 'Bathymetric surveys of Brown Bay, O'Brien Bay and Newcombe Bay in the Windmill Islands' was used as input data.
The comma delimited data resulted from bathymetric surveys of Brown Bay by Jonny Stark (AAD) in February and March 1997 includes latitude, longitude and depth fields. ... Latitude and longitude were obtained from differential GPS.

When viewing the Brown Bay soundings in conjunction with the Australian Antarctic Data Centre's coastline data and a Landsat 7 satellite image (path 104, row 107, captured 5 February 2000) it was apparent that there was a horizontal shift in the soundings. This may have arisen due to the problems with establishing the location of the GPS base station. Consequently, in consultation with Johnny Stark, a horizontal shift was applied to the soundings. The shifts applied were: easting +11.5 m, northing +21.3 m.

The shifted soundings were explored using the ArcGIS Geostatistical Analyst extension ESDA tools to identify and remove outliers in the data. Soundings that seemed irregular were deleted. Soundings that were positioned above the current coastline data were deleted although the coastline data were not used as input data for the dem.
Vertices from the Australian Antarctic Data Centre's terrestrial contour data in the Brown Bay area (Dataset_id 11, Qinfo 17) were added to the soundings. Half of this combined point data was used as a training dataset to create the DEM. The other half was retained as a test dataset to use to validate the DEM.

The creation of the DEM (0.5m cell size) was done in ArcGIS 9.2 using the Geostatistical Analyst extension, with the input data in a UTM zone 49 projection.

In Geostatistical Analyst:
The input data was split into a training and validation (test) dataset.
the DEM was interpolated from the training dataset using a Kriging method;
the DEM was cross validated using the training dataset; and
the DEM was validated using the test dataset.

Contours at 0.5m interval were generated from the DEM using the Spatial Analyst extension. Contours were smoothed and simplified using a tolerance of 1.5m . Contours greater than zero were exported to a terrestrial contour dataset called Contour_ln. Contours less than or equal to zero were exported to a bathymetric contour dataset called Bath_contour_ln.
The zip file available for download includes the training and test datasets as shapefiles, the DEM in ESRI's ArcInfo interchange and ASCII formats, files documenting the Kriging method and the validation results, and the terrestrial and bathymetric contours derived from the DEM.

THE DATA ARE NOT FOR NAVIGATION PURPOSES

Access Constraints The DEM is stored as an ESRI grid, a dem.asc - Arc/Info GridASCII format (Grid) and dem.e00 - Arc/Info export format (Grid).
The terrestrial contour and bathymetry contour data are stored in esri shapefile format.

Use Constraints This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Must be cited properly. Usually mapped to a Universal Transverse Mercator projection, Zone 49S, Datum WGS-84.

Please follow instructions listed in the citation reference provided at the URL below when using these data.

Ancillary Keywords

DEM

Windmill Islands

Data Set Progress

COMPLETE

Originating Center

Australian Antarctic Data Centre, Australia

Data Center

Australian Antarctic Data Centre, Australia

Data Center URL: http://data.aad.gov.au
Dataset ID: brownbay_bathy_dem

Data Center Personnel
Name: DATA OFFICER AADC Phone: +61 3 6232 3244 Fax: +61 3 6232 3351 Email: metadata at aad.gov.au Contact Address: Australian Antarctic Division 203 Channel Highway City: Kingston Province or State: Tasmania Postal Code: 7050 Country: Australia

Distribution

Distribution Media: HTTP

Distribution Size: 7183 KB

Distribution Format: ARCE, DEM, SHP, ASCII

Fees: Free

Personnel

JONATHAN SEAN STARK

Role: INVESTIGATOR

Phone: +61 3 6232 3589

Fax: +61 3 6232 3158

Email: jonny.stark at aad.gov.au

Contact Address:

Australian Antarctic Division

203 Channel Highway

City: Kingston

Province or State: Tasmania

Postal Code: 7050

Country: Australia

ANGELA BENDER

Role: TECHNICAL CONTACT

Role: DIF AUTHOR

Phone: +61 3 6232 3246

Fax: +61 3 6232 3351

Email: gis at aad.gov.au

Contact Address:

Australian Antarctic Division

203 Channel Highway

City: Kingston

Province or State: Tasmania

Postal Code: 7050

Country: Australia

Creation and Review Dates

DIF Creation Date: 2008-07-01

Last DIF Revision Date: 2008-10-21

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