Peeling Back Landsat’s Layers of Data

Landsat satellites circle the globe every 99 minutes, collecting data about the land surfaces passing underneath. After 16 days, the Landsat satellite has passed over every spot on the globe, and recorded data in 11 different wavelength regions.
The individual wavelength bands can be combined into color images, with different combinations of the 11 bands revealing different information about the condition of the land cover.

The Landsat program is jointly managed by NASA and the USGS:
– http://www.nasa.gov/Landsat
– http://landsat.usgs.gov