Flight campaigns named SVALEX (Svalbard Experiment) and ICESAR (Synthetic Aperture Radar for Ice) were carried out over sea and land ice around Svalbard in winters 2005 and 2007, respectively. Here we report on the sea ice part of these campaigns. The objectives were to collect data for studying the effect of sea ice roughness on the atmospheric boundary layer, and for investigating the retrieval of characteristic ice surface roughness parameters from radar images acquired at different frequencies and polarizations. Data of the ICESAR-campaign will also be used for simulating image products of the planned GMES Sentinel-1 mission and for looking at the pros and cons of the various imaging modes for sea ice mapping. In this paper, we present a short summary of the measurements and the planned data analyses.