Satellite Eye for Galathea 3

Antarctica is seen from the ASAR instrument on-board ENVISAT.

It is clear to see the many satellite-paths from which the image is composed. The width of a single path is around 420 km. The radar images are recorded both day and night so it is possible to produce this type of images year round. Each image has a spatial resolution of around 1 km but the composed (mosaic) image shown here only shows around every 6th pixel.

There is an overlay of contour lines that indicate the sea concentration of 30% (blue), 60% (green) and 90% (orange). The coastline is red. The data are observed from AMSR.

Both in the Ross Sea (in the bottom) and the Weddell Sea (upper left) areas are found with scattered sea ice outside the 30% contour line.

Technical information:

This is an ASAR mosaic of Antarctica recording between 11 and 13 Januar 2007. AMSR is a microwave radiometer from NASA. We use it to produce daily maps of the spatial extend of the sea ice. The AMSR instrument records the thermal (natural) microwave radiation emitted from the surface of the Earth at various wave-lengths, and as the radiation from ice is much higher than the radiation from ocean, it is possible to calculate how much ice there is within the field of view.

The 'original' mosaic at 1 kilometers resolution (16 MBytes) is found at:

http://galathea.oersted.dtu.dk/images/
20070113.envisat.s.GMM.1km3daymosaic.jpg

The data are collected and processed by the Danish Space Centre, DTU, http://www.oersted.dtu.dk/