The Landsat Image Mosaic of Antarctica and the New Antarctic Web Portal Interactive Viewer

Two digital mosaics of Antarctica are being produced from Landsat-7 imagery collected during 1999-2001. The US Geological Survey and NASA (with NSF support) and the British Antarctic Survey (BAS) are cooperating to complete the project by the beginning of the International Polar Year (IPY). One mosaic will be constructed from the 15-meter spatial resolution panchromatic data. The other will be a three-band true color mosaic at 30- meter resolution. Slightly more than 1000 scenes have been selected to allow a nearly cloud-free mosaic and a perimeter that avoids most discontinuities caused by episodic calving. Images will be converted to surface reflectance before mosaicing and the final mosaics will be enhanced to emphasize textures in both the rock and snow surfaces. The mosaics and the full 8-band multispectral data of the individual scenes used in the mosaic will be available to the public via a new Antarctic Web Portal Interactive Viewer similar to the viewer now used by the USGS to serve National Map data to the public. This viewer allows the user to layer multiple data sets, zoom, scroll and select specific areas for data downloading. Among the data sets to be available along with the Landsat mosaics are the mosaics of Antarctica constructed from Radarsat and MODIS data as well as other existing USGS and BAS data of Antarctica. The viewer serves data in a standard WMS format allowing it to serve a virtually unlimited suite of data hosted either by the USGS or separately by cooperating organizations. This flexibility is intentional to influence the construction of, and the sharing of existing and new Antarctic data sets collected during the IPY. Data hosting by the USGS ensures the long-term stability and 24/7 availability of these valuable data sets commensurate with the data principles adopted for the IPY.