Contents I. Introduction
The physical principle behind remote sensing is that the energy level of each photon of electromagnetic radiation determines its wavelength, hence any electromagnetic radiation can be described in terms of its wavelengths. This is also true for the reflectance, that is the percentage of light reflected by an object. The molecular structure of each object determines its reflectance, and it is possible to analyze the spectra of the light that has been reflected so to recognize the material(s) that make up the observed object.
