This map shows the distribution of the iceberg data extracted from ERS SAR images. Icebergs are identified in Synthetic Aperture Radar [SAR] images by image analysis using the texture and intensity of the microwave backscatter observations. The images are segmented using an edge detecting algorithm, and segments identified as iceberg or background, which may be sea ice, open water, or a mixture of both. Dimensions of the icebergs are derived by spatial analysis of the corresponding image segments. Location of the iceberg is derived from its position within the image and the navigation data that gives the location and orientation of the image. More than 20,000 individual observations have been extracted from SAR images acquired by the European Space Agency's ERS-1 and 2 satellites and the Canadian Space Agency's Radarsat satellite. Because images can overlap, some proportion of the observations represent multiple observations of the same set of icebergs. Most observations relate to the sector between longitudes 70E and 135E. The data set includes observations from several other discrete areas around the Antarctic coast. In general observations are within 200 km of the coast but in limited areas extend to about 500 km from the coast. This metadata record has been derived from work performed under the auspices of ASAC project 2187 (ASAC_2187). The map in the pdf file shows the extent of the coverage of individual SAR scenes used in the analysis and the abundance and size characteristics (by a limited colour palette) of the identified icebergs.

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• AAD_Ant_iceberg_SAR

AU_AADC Short Name: AAD_Ant_iceberg_SAR Version ID: 1 Unique ID: C1214311458-AU_AADC

The 'Australian Antarctic Territory coastline 2003' dataset is a digital vector representation of the coastline of Antarctica, between 45 to 160 degrees east, based on both the edge of permanent ice and grounding line, derived by means of remote sensing interpretation. A 'proof of concept' methodology over a test area was carried out to compare a number of complementary remote sensing techniques, including interferometry and airborne ice radar profiling, to confirm validation of grounding line as mapped from Landsat 7 ETM+ imagery. This methodology concept then served to validate grounding line locations elsewhere along the coast of the AAT. The National Mapping Division of Geoscience Australia and the Australian Antarctic Division developed this dataset as a joint project. Where available, Australian Antarctic Division supplied large-scale vector data of various areas around the AAT, which were included as part of the main coastline dataset. These included: * Holme Bay 1:25,000 GIS dataset * Larsemann Hills - Mapping from aerial photography captured February 1998 * Rauer Group 1:50000 Topographic GIS Dataset * Vestfold Hills Topographic GIS Dataset * Windmill Islands 1:50000 Topographic GIS Dataset * Cape Denison and McKellar Islands GIS dataset from Ikonos satellite imagery Refer to the metadata record for each of these datasets for further information. The coastline dataset is comprised of three parts: one polygon coverage consisting of ice features, and another one consisting of coastal features. A third coverage consists of only island point features (islands too small to be shown as polygons). This dataset supersedes the Australian Antarctic Territory Coastline 2001 dataset which is also part of SCAR's Antarctic Digital Database (ADD) version 4 and version 5. It replaces data digitised from Landsat 4 and 5, with that from Landsat 7 ETM+, because of its more reliable positional accuracy and more recent acquisition. The Australian Antarctic Territory Coastline 2001 dataset and metadata record have been archived. Please contact the Australian Antarctic Data Centre if you would like a copy of this data and metadata.

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• AAT_Coastline_2003

AU_AADC Short Name: AAT_Coastline_2003 Version ID: 1 Unique ID: C1214305672-AU_AADC

An image correlation technique has been applied to RADARSAT ScanSAR images from November in 1997, and November 1999, to create the first detailed maps of fast ice around East Antarctica (75E-170E). This method is based upon searching for, and distinguishing, correlated regions of the ice-covered ocean which remain stationary, in contrast to adjacent moving pack ice. Within the overlapping longitudinal range of ~86E-150.6E, the total fast-ice area is 141,450 km2 in 1997 and 152,216 km2 in 1999. Calibrated radar backscatter data are also used to determine the distribution of two fast-ice classes based on their surface roughness characteristics. The outer boundaries of the determined fast-ice area for November in 1997 and 1999 are contained in the data files for this record. This work has been allocated to ASAC project 3024.

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• fast_ice_1997_1999

AU_AADC Short Name: fast_ice_1997_1999 Version ID: 1 Unique ID: C1214308565-AU_AADC

This dataset is a Digital Elevation Model (DEM) of Heard Island derived by interferometric processing from RADARSAT images acquired on 17 February 2002 and 13 March 2002. The DEM was created by a contractor for the Australian Antarctic Data Centre. The cell size is 10 metres. Processing stages included: 1 Detection of a coastline from a RADARSAT image of Heard Island acquired 24 January 2002 and rectified using ground control points provided by a second contractor. 2 Generation of the interferometric SAR (InSAR) DEM using the RADARSAT images acquired on 17 February 2002 and 13 March 2002. 3 Co-registration of the InSAR DEM with a DEM derived from stereoscopic RADARSAT images acquired in March and April of 1997 and described by the metadata record 'Heard Island RADARSAT (1997) DEM'. 4 Merging of the InSAR DEM with the 1997 stereoscopic DEM and the coastline detected in stage 1. The following are available for download from the Related URLs below: 1 The final DEM in ArcInfo interchange or ArcInfo ascii formats. 2 The rectified RADARSAT image of Heard Island acquired 24 January 2002. Rectified using ground control points and subsequently used in processing of the DEM. 3 Contours generated from the DEM and the island polygon (coastline) extracted from the rectified RADARSAT image acquired 24 January 2002. 4 A detailed deport describing the generation of the DEM. 5 A report by Dr Arko Lucieer Centre for Spatial Information Science School of Geography and Environmental Studies University of Tasmania Private Bag 76 Hobart 7001 Tasmania, Australia outlining some errors and artefacts in the DEM. Dr Lucieer produced this report while working for the Australian Antarctic Division. On 3 July 2003 Henk Brolsma (Mapping Officer, Australian Antarctic Division) wrote the following email to the contractor who created the DEM. "What I'm really interested in are the 20 metre contours for the areas with high coherency. These are the areas where most of the field work takes place and where we have a need for contours with an accuracy better than 50 metres and my reason for using INSAR in the first instance. So can you send me: 1. The 20 metre contours for the areas with high coherency? 2. The zone or line where the INSAR and Stereo Imagery were integrated? This would be very useful for the metadata." He did not receive a reply to that email and that was the reason why he was reluctant to make the DEM public. Since he won't now get a reply and the DEM is probably better than the 1997 DEM, he considers the 2002 DEM should now be published.

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• heard_dem_radarsat02

AU_AADC Short Name: heard_dem_radarsat02 Version ID: 1 Unique ID: C1214308612-AU_AADC

The orthophoto mosaic is a rectified georeferenced image of the Heard Island, Laurens Peninsula Coastal Area. Distortions due to relief and tilt displacement have been removed. Orthophotos were derived from non-metric cameras (focal length unknown).

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• photo_mosaic_laurens_or

AU_AADC Short Name: photo_mosaic_laurens_or Version ID: 1 Unique ID: C1214311224-AU_AADC