Physics of RS

Most remote sensing instruments on aircraft or space-based platforms operate in one or more of these windows by making their measurements with detectors tuned to specific frequencies (wavelengths), that pass through the atmosphere. The behavior of electromagnetic waves in free space is governed by Maxwell's equations. In homogeneous, isotropic and nonmagnetic media, Maxwell's equations can be combined to derive the wave equation, in the case of a sinusoidal field. Remote sensing instruments exploit different aspects of the solution to the wave equation, in order to learn more about the properties of the medium from which the radiation is being sensed. The electromagnetic energy can be presented in a quantized form, as bursts of radiation with a quantized radiant energy, which is proportional to the frequency. The polarization states of the incident and reradiated waves play an important role in remote sensing.