The project aims to determine the accuracy with which future measurements of the mass balance of the polar ice sheets will be made. There is a need to know the mass balance of Greenland and Antarctica to assess their potential impact on sea level rise and sensitivity to the range of possible future climates. There is general agreement that the ice sheets are currently losing mass but the range of estimates and uncertainty in those estimates is, in many cases, larger than the loss, particularly regionally. One method of determining ice sheet mass balance is to repeatedly measure the ice sheet surface elevation and determine how it is changing. This elevation change can then be converted to a volume of ice and a contribution to sea level.

CryoSat 2 is a new satellite, launched by ESA, carrying onboard a radar altimeter which will determine the height of the ice sheet surface with unprecedented accuracy. However, the radar waves penetrate into the surface of the ice sheet and the penetration depth and its changes under different weather conditions is currently poorly understood. In this project, the Cryosat-2 data will be compared with similar data from airborne instruments as well as airborne laser altimeters. The laser instruments do not penetrate into the ice sheet surface and so comparison of these data will allow to determine the amount of penetration and how this varies throughout the year.