SAR Image Analysis to Estimate Freeze-Thawdates for a High Latitude Lake in Alaska

This paper presents a novel method to estimate freeze-thaw dates of a small lake, with area 10 km², using SAR data from RADARSAT-1 remote sensing spacecraft. The algorithms analyze an annual time series of the difference in average backscatter, between the lake and the surrounding region, to estimate the day of occurrence of the respective lake ice event. The initial results obtained, using multi-year data from a northern high-latitude lake, are promising. The mean absolute error in estimating the thaw date is 0.7 days and for the freeze date it is 4 days. These results encourage further testing of these algorithms on lakes in other geographic regions.