Lake Superior ice viewed using RADARSAT-1 ScanSAR imagery and low-altitude oblique air photos

Ice is a major component of the Great Lakes hydrologic cycle, controlling or influencing winter lake-atmosphere energy budgets, weather, ecology and human activities. RADARSAT-1 ScanSAR synthetic aperture radar (SAR) imagery provides new opportunities for synoptic, moderate-high resolution observation of the Great Lakes ice environment. This paper presents ScanSAR imagery and low-altitude oblique air photos to (a) illustrate SAR expressions of typical Lake Superior ice features and (b) indicate the utility of such oblique air photos as ground truth for SAR validation. SAR imagery reveals a diversity of ice types and conditions, and captures rapidly evolving conditions in the Lake. Contemporaneous oblique air photos reveal essential information about ice conditions, but due to inherent geometric distortions tend to be difficult to correlate with relatively more planimetric SAR imagery.