CryoSat was designed to be fully automated such that its three measurement modes would be switched on-board according to the geographic chart. Low Resolution Mode (LRM) would have been operated over the light-blue areas of the ice-sheet plateaux and over the oceans. Synthetic Aperture Radar (SAR) mode would have been exploited over medium-blue sea-ice areas (the chart was to be updated every month for seasonal changes in sea-ice extent). SAR Interferometric (SARIn) mode was to be used over the dark-blue steeply sloping ice-sheet margins, small ice caps and areas of mountain glaciers. The red areas on the chart indicate where calibration and validation activities would have been carried out.