The overall objective of SITHOS is to develop European monitoring systems for sea ice thickness and related parameters for climate change detection, support to sea transport, offshore operations as well as environmental protection in polar regions. SITHOS will include pre-launch validation experiments for CRYOSAT, a European Satellite to be launched in 2004 with global sea ice thickness observation as a key objective.

Specific objectives of SITHOS:

• Develop and test a portable ice thickness observation system based on a combination of electromagnetic induction and laser altimetry (EML – method) for use on ships, helicopters and fixed-wing aircraft.

• Develop and test automatic ice stations (AIS) for observation of ice thickness and related parameters which can be deployed on ice floes, transmit data in real time via satellite and operate for several years.

• Obtain, analyze and assess upward looking sonar (ULS) data from autonomous underwater vehicles (AUV) and from submarines. Develop techniques to measure ice topography and thickness by aircraft laser and GPS.

• Investigate and validate methods to measure ice freeboard and thickness by use of spaceborne altimetry as preparation for use of CRYOSAT data.

• Improve sea ice modelling capability using data obtained by the observational methods, listed above, and define the requirements for sea ice thickness and other ice data from modelling perspective

• Assess the different ice thickness observation methods and make recommendation for possible synergetic use of these techniques in operational ice monitoring of the polar seas.