AVHRR
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The development of an operational sea ice mapping system. This metadata record refers to the development and testing of an prototype system, ICEMAPPER, to interpret NOAA AVHRR imagery on a semi-automatic basis, off the Southern Ocean near to the Antarctic coast. From the abstract of one of the referenced papers: This paper reports work towards the development of a semi-automated technique for creating sea-ice and cloud maps from Advanced Very High Resolution Radiometer (AVHRR) images of the Southern Ocean near to the Antarctic coast. The technique is implemented as a computer-based system which applies a number of classification rules to the five bands of an AVHRR image and classifies each pixel in the image as representing open water, low cloud, high cloud or one of several different sea ice concentration categories. The map produced by the system is then displayed and an experienced sea ice forecaster evaluates the result. If it is deemed satisfactory the map is saved on disk. If not, the expert can alter various parameters within the classification rules to produce a satisfactory map. Experience so far has shown that judicious, but reasonably minor, changes to the rule parameters can produce a satisfactory sea-ice map relatively quickly in most cases. The system is also capable of effectively distinguishing cloudy from clear pixels but it does not accurately distinguish high cloud from low cloud in some of the images. Current work is being undertaken to improve the cloud classification rules.
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This Atlas presents a compilation of AVHRR satellite images of sea ice adjacent to the coast of Eastern Antarctica. It is produced primarily for use by marine and vertebrate ecologists within the Australian Antarctic Division and as a contribution to the CCAMLR Ecosystem Monitoring Program. It is anticipated that this atlas will have value to a wider range of research and other uses including shipping operations. The Atlas provides one good image for each month between 1992 and 1999 for each of 5 regions of Eastern Antarctica centered on the following Antarctic Stations. Mawson station (M) - latitude 67 degrees 36.3 minutes S, longitude 62 degrees 52.2 minutes E Davis station (D) - latitude 68 degrees 34.6 minutes S, longitude 77 degrees 58.3 minutes E Casey station (C) - latitude 66 degrees 17.0 minutes S, longitude 110 degrees 31.2 minutes E Dumont D'Urville station (DD) - latitude 66 degrees 39.8 minutes S, longitude 140 degrees 00.1 minutes E Terra Nova Bay station (TN) - latitude 74 degrees 41.7 minutes S, longitude 164 degrees 07.0 minutes E Each image has been renavigated onto the same projection (Polar stereographic), gridded and a coastline added. Visible and thermal images are provided for the austral summer months, while only a thermal image is provided for the dark winter months. Due to either missing data or the lack of suitable imagery it has not been possible to provide a complete coverage over the period in all regions. Those 500 images presented were culled from some 20,000 images consulted. Images are presented with a schematic map indicating the major divisions of the image into open water, sea ice, cloud, land etc. Each month is accompanied by a short description of the sea ice conditions. The concept of a Sea Ice Atlas for scientific purposes was first proposed in 1999 and funded by the Australian Antarctic Division on the recommendation of the ANARE Mapping and Geographic Information Committee in 1999. Dr Kelvin Michael at IASOS was contracted to supervise the project and produce the Sea Ice Atlas in both hard copy and digital format. The AVHRR data are down loaded at the HRPT receiving facility Australian Antarctic Station of Casey. The HRPT archive is kept at the Antarctic Climate and Ecosystems CRC at the University of Tasmania.