Satellite Eyes - Seeing Beyond the RainbowSatellites like
Landsat can have sensors which "see" in visible light, but they
may also be able to record radiation (such as infrared) that it
is beyond our capability to see. The Electromagnetic Spectrum
Visible light is only one kind of electromagnetic radiation that
satellites can monitor. Infrared and radar are also part of the
electromagnetic spectrum, and each represents radiation in a
different wavelength. For example, yellow light has a longer
wavelength than blue, and red is longer than yellow. Infrared
and radar wavelengths are longer still. By collecting data in
different regions of the spectrum, satellites can reveal
information that would go undetected by our eyes alone. Thermal
infrared image from the Heat Capacity Mapping Mission (HCMM).
This scene covers 15 times the area of a Landsat frame but can
only resolve features larger than 600 meters (about 1900 feet).
The warmest areas of the region, which show up in the lightest
tones, are the deserts of Ar