The knowledge of the cryosphere's mass balance is fundamental to understanding the impacts of climate change. Much of the research into the key components of the cryosphere is based on measurements of ice surface height, sea ice thickness, and snow morphology. A large amount of this information is derived from satellites. In order to make this information reliable it is derived from algorithms ... developed and tested with robust ground truth data, which is reference data of physical snow and ice properties collected on the ground. The objective of this research is to obtain improved information of the polar cryosphere derived from remote sensing data, in particular from ESA’s Cryosat satellite. Cryosat, one of the European Space Agency’s Earth Explorer missions, will be launched in 2009. Internal snow layers of the upper 10m were measured using ground penetrating radar (GPR) in two 800x800m grids at McMurdo Ice Shelf and in one 250x250m grid at Ross Island. Grid spacing is 100m, one bamboo stake was installed at every grid node to measure accumulation directly, to guide GPR measurements, and to measure ice dynamics. Radar frequencies used were 500 and 1000 MHz. The measurement sites at McMurdo Ice Shelf are located on a Cryosat subsatellite track, in between both sites. 19 additional stakes were installed every 1.6 km and radar data were collected. Snow pit measurements were made at all three measurement sites.