Scientists spend a white Christmas in Antarctica   Clearing the camp of dry Antarctic snow. The dry Antarctic snow also blows in on the wind and drifts up against the tents.   CryoSat will acquire accurate measurements of the thickness of floating sea-ice so that seasonal to inter-annual variations can be detected. CryoSat will also survey the surface of continental ice sheets to detect small elevation changes. CryoSat's high spatial resolution radar altimeter is capable of operating in a number of modes, optimised for measurement over different surfaces.   Taking a tea break out on the blue ice. The sledges are loaded with petrol, camping gear, a survival kit, food and of course scientific equipment. All trips out are being used to survey the height of the ice surface using kinematic GPS. The Global Navigation Satellite System (GNSS) antenna mounted on the tripod is on the back of the sledge. The picture shows a blue ice area without snow cover.   In order to achieve highest accuracies with GPS, the kinematic measurements need to be related to a static reference station. Four reference stations are being used in total, three on bedrock and this one at the field camp. The picture was taken late in the evening - currently the Sun is above the horizon 24 hours a day.   Antarctica showing the location of the blue ice region where come of the validation activities to support ESA's CryoSat mission are being carried out. Release date: 14 January 2010