Multispectral Imagery

General principles of imaging are based on the registration of electromagnetic energy in particular zones of the electromagnetic spectrum using a particular sensor. In classical photography, reflected sunlight is registered in light-sensitive film. The first photographic films were sensitive in the visible spectral zone and had only one layer to record the integral amount of acquired energy; the films (and produced photographic prints) were black-and-white. The later films were composed of three layers, sensitive to three primary colors—red, green, and blue—which allowed us to develop true-color photographs, again, in the visible spectral zone, where human eyes perceive reflected sunlight radiation. Multispectral imaging systems simultaneously obtain a series of images recorded at a number of different spectral zones, far beyond the visible light. Multispectral imaging is ...