CryoSat pre-launch calibration and validation studies of sea ice thickness

This report provides an overview of snow and ice measurements form several field experiments providing useful data for CryoSat pre-launch studies related to sea ice thickness. The most extensive experiments were performed during the Polarstern cruises in the Barents Sea / Storfjorden area in March 2003 and in the area north of Svalbard in April 2003. In addition, summer experiments were conducted during expeditions with the Lance in the Fram Strait in 2003 and 2004. The experiment used a number of different observing techniques from satellites, aircraft, helicopter and in situ observing systems. Several new and unique measurements techniques for sea ice properties were tested and used in combination with established methods.
Comparison of methods used simultaneously over the same area is an important part of the work because more established methods can be used to validate new methods. For example, use of the helicopter EM system which has been developed over many years, was successfully used to validate the airborne laser-derived thickness estimates. In situ measurements obtained by drilling holes and using ground penetrating radar give detailed data on local scale. But spatial coverage of these data is very limited and it is challenge to obtain representative measurements for large parts of the Arctic sea ice.