Synergestic use of RADARSAT, ERS and "Okean" radar images for sea ice studies in the Northern Sea Route

In April-May 1998 sea ice conditions in the Barents and Kara Seas were studied from synchronous RADARSAT, ERS and "Okean" radar images. SAR images were transmitted in quasi-real time onboard nuclear icebreaker "Sovetsky Soyuz" and signatures of the main sea ice types and features were retrieved and compared with subsatellite observations. RADARSAT and ERS signatures of first-year ice are rather similar, whereas for gray and new ice they can be different. Analysis of synchronous RADARSAT and "Okean" images proved, that large-scale ice features can be identified from both images, whereas navigationally important small-scale features-only from SAR.