Q. Define the spectral resolution of satellite?

Spectral resolution : The sensitivity to different features of earth is the most important aspects considered in the spectral resolution.

The earth features can be divided broadly into three types, viz, healthy green vegetation, dry bare soil and clear lake water. It has been observed that each of these features has a clear and distinct average reflectance curves in visible electromagnetic range. However, in the nature, such features are rarely found in their pure form. The vegetation, according to their environmental conditions, have a range of reflectance depending upon the types, their water contents, stresses, diseases, etc. Similarly, the reflectance from the soil changes according to its moisture contents, soil textures, surface roughness, iron contents, organic contents, etc. The reflectance of the clear water is highly influenced by turbidity, algae contents, oil and other industrial / chemical wastes, etc.

Advantage of these characteristics is taken by taking observations in different band frequencies of electromagnetic waves within visible light range and infrared range. Different sensors are assigned separate narrow bands. Different bands help to give different identifications and classifications to the objects viewed using the data.