Sea ice

Sea ice monitoring tracks ice presence, concentration, extent, type, thickness indicators, and navigation-relevant conditions across polar waters.^[1][2][3]

Passive microwave sensors provide the long continuous satellite record for sea-ice concentration and extent because microwave contrast between ice and open water is observable day and night and through most clouds.^[1][2]

SAR, including Sentinel-1, is a primary high-resolution route for operational ice charts, ice edge, iceberg, and navigation-relevant ice condition mapping.^[3][2]

Sea-ice type, thickness, and freeboard require additional methods and validation, and concentration and extent are more mature than thickness retrieval.^[1][2]