Topographic properties of sea ice surface roughness in both cryosat-2 and SAR sub-footprint scale

Knowledge of the spatial variability or patchiness of the sea-ice roughness is currently rather limited. Most of the earlier studies has been based on 1D laser altimeter measurements, airborne or satellite. Majority of the studies that use 2D laser altimeter data are however using 1D statistical methods for the data analysis, the focus being still on the elevations not on the 3D structure of the ice surface. In this case study a new approach was used: the topographic properties of the sea ice surface were studied in sub-footprint scale by using terrain analysis techniques. The presented study and preliminary results are one part of ANTLOAD project: `quantify Antarctic ice thickness by in situ observations, radar altimeter and modeling and use the results to assess the performance of ice going ships'.