Soon after their development, cameras became one of the first true remote sensing tools when they were first flown on balloons, then airplanes and later spacecraft. Special films extend the range of cameras beyond visible light to infrared and ultraviolet. Modern remote sensing includes the entire electromagnetic spectrum from radio waves through microwaves, millimeter waves, submillimeter waves, infrared, visible, ultraviolet, x-ray and gamma rays. The spectrum range is important because the world looks differently at different parts of the spectrum due to variations in electrical and mechanical properties. In the visible light range we call this effect 'color'.
Color helps discriminate between objects and various surface properties.
High altitude aircraft and satellites allow acquisition of remotely sensed data over large scale regions, giving us a global view of the Earth. The impact of remote sensing can not be understated. Sensors on weather satellites routinely return vital weather information which help farmers protect crops, forecast storms, monitor climate, and track pollution. Remote sensing has enabled scientists to better understand the global atmosphere, the oceans, vegetation cover and their interrelationship. It is beginning to help us understand the impact of modern civilization on the planet and its biosphere.