Snow cover state evaluation. This evaluation is based on combined optical and infrared observations (albedo and temperature measurements). Limitations: bad weather or low solar illumination in winter; rather small coverage.

Reference: quoted in “Monitoring Dry, Wet, and No-SnowConditions From microwave Satellite Observations” (Alain Royer, Kalifa Goïta, Jacqueline Kohn, and Danielle De Sève)