What are the various types of satellite imagery available?
A. There are four principal types of satellite imagery used in operational and research meteorology. Each has its advantages and disadvantages. Many examples of each type can be found at meteorology related web-sites. 1. Visible Imagery (VIS) Images obtained using reflected sunlight at visible wavelengths, in the range 0.4 to 1.1 micrometres. Visible imagery is displayed in such a way that high reflectance objects, e.g. dense cirrus from CB clusters, fresh snow, nimbostratus etc., are displayed as white, and low reflectance objects, e.g. much of the earth’s surface, is dark grey or black. There are grey shades to indicate different levels of albedo (or reflectivity). Very dependent upon angle of incident sunshine, and of course, not available at night, though some military/research satellite sensors can utilise reflected moonlight to detect cloud. 2. InfraRed(IR) These images are obtained by sensing the intensity of the ‘heat’ emissions of the earth, and the atmosphere/atmospheric cons
