Monitoring of sea ice motion by sequential satellite images

The technique of using time series of satellite images to track ice motion has been demonstrated with the ERS Synthetic Aperture Radar (SAR) data in several test areas in the Northern Sea Route. Estimation of ice motion is done semi-automatically by recognizing ice features (floes, cracks, etc.) in sequential images of the same area. SAR images from ERS-1 3-day 'Ice orbit' in January-March 1994 have been used to compute sea ice displacement in several subsequent 3-day intervals, A case study was performed in the south west Kara Sea area, just east of Vaygach Island. Highly variable ice velocities over a 2 week period due to changing wind conditions were found. Also a synoptic mapping of the ice velocities in the region from Pechora Sea to Ob estuary were produced. For the first time RADARSAT ScanSAR data were used to estimate sea ice motion in the Laptev Sea, near the Vilkitsky Strait, The 500 km wide swath covered by a ScanSAR image, improve the time and spatial resolutions of the ice displacement calculation compared to ERS SAR images. With RADARSAT ScanSAR, and ENVISAT ASAR from 2000, it will be possible to cover the whole Arctic sea ice with SAR data every day.