There are many wavelengths of light, but our eyes can only detect the visible wavelengths near the middle of this scale. Remote sensing satellites also use many infrared wavelengths. Radar sensors operate in microwave wavelengths. Other remote sensing satellites detect longwave infrared and microwave emissions from the Earth and the atmosphere.

For a more detailed model of the Electromagnetic Spectrum, including a comparison of wavelengths to frequencies, see Charles Lucy’s Tuning;