This dataset is a collection of points that describe the location and size of icebergs surrounding the Antarctic continent. The points locations are in Polar Stereographic -71 latitude (with corresponding x, y geographic coordinates) The dataset was extracted and compiled using a novel technique from the 'RAMP AMM-1 SAR Image Mosaic of Antarctica (Version 2)' available from the National Snow and Ice Data Center (NSIDC) at https://nsidc.org/data/NSIDC-0103/versions/2. The data are available in NetCDF and csv formats.

Envisat was was launched on 01/03/2002, by ESA and operated until 08/04/2012. It provided suitable imagery for the austral winters (May - November) of 2007 to 2011. Envisat caried a C-band (5.33 GHz; wavelength ∼ 5.6 cm) Advanced Synthetic Aperture Radar [ASAR], capable to acquire data in multiple modes (image, alternating polarization, wave, ScanSAR (wide swath), and ScanSAR (global monitoring)) at various incidence angles and in several polarisations. Of ASAR's five distinct measurement modes, the following two modes may be used to derive sea-ice motion from overlapping images in our project: 1. ASAR Wide Swath Mode -- 400 km by 400 km wide swath image. Spatial resolution of approximately 150 m by 150 m for nominal product. VV or HH polarization. 2. ASAR Global Monitoring Mode -- Spatial resolution of approximately 1000 m in azimuth by 1000 m in range for nominal product. Up to a full orbit of coverage. HH or VV polarization. For further detail, see ESA's Copernicus web portal. Sea-ice motion is derived from suitable SAR image pairs with sufficient spatial overlap but relatively short time separation, i.e. ideally 6days or less. Image-crosscorrelation analysis is employed to identify displacement vectors within the image pair. The underlying processing and analysis is part of the (mostly) automated IMCORR [IMageCORRelation] Processing, Analysis and Display System [IPADS]. This study uses C-band (HH polarisation) ASAR scenes, with an image pixel size of 75 m across a 405 km swath. -- For further information see Giles et al., Semi-automated feature-tracking of East Antarctic sea ice from Envisat ASAR imagery, Remote Sensing of Environment, 115, 2267-2276, 2011. Acknowledgement: All Envisat ASAR data are courtesy of the European Space Agency, and were obtained under agreement with ESA. The International Space Science Institute (ISSI), Bern, Switzerland, is acknowledged for supporting this study via Projects 137 and 169.

Sea-ice motion derived from two (partially) overlapping ESA Sentinel1 [S1]A or B scenes. Satellites S1A/B carry C-band (5.405 GHz) Synthetic Aperture Radar [SAR] sensors. For this data set images from the Extra Wide swath (EW) mode of operation (swath width 410 km) have been used. EW mode data are available as a medium-resolution ground range detected (GRD) product, i.e., resolution of 93 × 87 m and pixel size 40 × 40 m. Approximately two-thirds of the EW mode data recorded over the Antarctic area are dual-polarisation (HH + HV) products. The remainder are mainly single-polarisation (HH) products. For further detail, see ESA's Copernicus web portal. Ice motion is derived from suitable SAR image pairs with sufficient spatial overlap but relatively short time separation, i.e. ideally 6 days or less. Image-crosscorrelation analysis is employed to identify displacement vectors within the image pair.

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.

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.

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.