Antarctica CryoSat-2 DEM

ESA has published a new Digital Elevation Model (DEM) of the Antarctic ice-sheet and ice-shelves produced using data acquired by the CryoSat-2 radar altimeter. Posted on a 2 x 2 km grid, the DEM provides an elevation measurement for 97% of the floating ice-shelves and 91% of the grounded ice-sheet, up to a latitude of 88 ° S. The remaining grid cells are interpolated to provide a continuous grid covering 100% of the ice-shelves and ice-sheet North of 88 ° S. The model utilizes both Low Resolution Mode and Synthetic Aperture Radar Interferometric Mode acquisitions from the baseline-c distribution of the level 2 product. In total, approximately 2.5 x 108 elevation measurements were used, acquired between July 2010 and July 2016. The accuracy of the presented model is assessed through comparison to approximately 1.9 x 107 airborne laser altimeter measurements from NASA IceBridge campaigns (more information available at https://nsidc.org/data/icebridge ) over the time period December 2008 to December 2014, in various locations across Antarctica. The initial input data were recorded by the SIRAL (SAR Interferometer Radar Altimeter) instrument, mounted on the CryoSat-2 satellite. Over the interior of the continental ice-sheet, data was selected from Level 2 Low Resolution Mode (LRM) data files. Over the ice-sheet margins and ice-shelves the chosen data came from Synthetic Aperture Radar Interferometric (SARIn) mode acquisitions (information regarding the geographical extent of the CryoSat-2 mode mask is available online at https://earth.esa.int/web/guest/-/geographical-mode-mask-7107 ). The Level 2 product has a series of geophysical corrections applied to correct the selected measurements for the following: off-nadir ranging due to slope, dry atmospheric propagation, wet atmospheric propagation, ionosphere propagation, solid earth tide and ocean loading tide. For both operating modes data from the baseline-c distribution of the Level 2 product was used. Over the LRM mode mask area elevation estimates were retrieved from CryoSat-2 waveforms using the OCOG retracking algorithm. For SARIn regions the Level 2 SARIn retracker was used. Data Access: The model will soon be freely available via the CPOM portal , which already provides information on sea-ice volume and thickness, ice velocity and, shortly, ice sheets. In the meantime, however, the model can be downloaded here . References http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/CryoSat_reveals_Antarctica_in_3D http://www.spacedaily.com/reports/CryoSat_reveals_Antarctica_in_3D_999.html http://homepages.see.leeds.ac.uk/~py10ts/cpom_cryosat2_antarctic_dem/product_user_guide/Antarctica_DEM_CryoSat2_Product_User_Guide_v1.2.pdf