The snow extents are derived using remotely sensed data, and they are based mainly on the relation between the radiative behaviour of the surface and the Fractional Snow Cover (FSC), also defined as the Fractional Snow-Covered Area (fSCA). This parameter describes the fraction of surface covered by snow in the picture element (pixel) of a remotely sensed image.
Select an image on the calendar and then click the button to see the raw and the processed image. The orange line on the processed image define the the border of the mask used by the algorithm [ref...]; the violet area is the snow covered area accordingly recognized.