Energy recorded by remote sensing systems undergoes
fundamental interactions that should be understood to properly
interpret the remotely sensed data.
For example, if the energy being remotely sensed comes from
the Sun, the energy:
is radiated by atomic particles at the source (the Sun),
propagates through the vacuum of space at the speed of light,
interacts with the Earth's atmosphere,
interacts with the Earth's surface,
interacts with the Earth's atmosphere once again, and
finally reaches the remote sensor where it interacts with
various optical systems, filters, emulsions, or detectors.