Satellite Image Home Page

Visible 0.4-1.1 µm

Visible (VIS) imagery is derived from solar radiation scattered or reflected towards the satellite from the earth-atmoshpere system. Visible images give meteorologists extra information that may not appear on Infrared temperature images. For example, fog appears in Visible images, but may not in Infrared images when the fog and the land are at the same temperature.

The intensity of the image depends on the albedo/reflectivity of the underlying surface or cloud. Visible images are only available during the daytime, because at night the world looks black. Early morning 7am VIS images show the sunlight rising in the east, and the 7pm VIS images show the sun setting in the west.

VIS images are normally displayed in a manner similar to that seen by the human eye. Using a black and white colour scale, with different shades of grey indicating different levels of reflectivity, the brightest and most reflective surfaces are in white tones and the least reflective in black. In general clouds are seen as white objects against the darker background of the earth's surface. The brightness also depends on the intensity of the reflectivity and the relative positions of the sun and satellite with respect to the earth. Shadows and highlights can be seen where the sun shines obliquely on to cloud.
[Source Bader et al, 1995]

Visible imagery is available on: