Interferogram from Austfonna
DEM generation and topographic analysis
1) Geometry and velocities will be derived from (1) Interferometric Synthetic Aperture Radar (InSAR) data10, (2) SAR speckle tracking11, (3) satellite and airborne optical stereo10, and (4) feature tracking based on repeat optical imagery12. Radar data will be taken from the ERS and ENVISAT satellites. Some interferograms are already available from cooperative partners (SPRI, USw). We also plan to use data from Terra SAR X and ALOS (radar sensor). Spaceborne optical data will be from Landsat, ASTER (stereo), Spot5 (stereo), ALOS (stereo) and IceSat (LIDAR altimeter). Together with ground-based velocity and ice thickness measurements, the data will give input to ice discharge, and calving rate calculations for Austfonna and Kronebreen/ Kongsvegen. CryoSat II altimeter data may be available at the end of the IPY project period, giving an excellent opportunity for future monitoring. Austfonna is a CalVal site for CryoSat.
2) Ice facies. Albedo variations and melt extent will be derived from radar satellite data13, optical ASTER and Landsat imagery (15 & 30m resolution), and MODIS and MERIS data (250-300 m resolution). Data will provide input to mass balance modeling and used to quantify supraglacial hydrology. Wintertime SAR-data will be used to map the superimposed ice zone14. Images from all available sources are available for the period 1975-2005, giving the opportunity to analyze time series.
3) Glacier extent and change. Area, length and front position of the target glaciers will be determined from optical imagery (e.g. ASTER, Landsat & Spot5), and compared with previous inventories and maps15,16. No detailed survey of the total glaciated area in northern Norway has been performed since the 1970s17. Geometric changes of Austfonna since the LIA (c.1900) will be mapped by combining all existing maps and aerial photography with recent ASTER-images.