The International Space Station (ISS) provides an excellent venue for observing Earth systems. Starting in March 2007 and coinciding with the beginning of the International Polar Year (IPY), NASA's Crew Earth Observations (CEO) payload invites IPY investigators to submit requests for relevant imagery be collected from the ISS.
Every day, ISS astronauts photograph designated sites and dynamic events on the Earth's surface using digital cameras equipped with a variety of lenses. Depending on observation parameters, astronauts can collect high-resolution (4–6 meter pixel size; see J. Robinson and C. Evans, Eos Trans. AGU, 83(17), 185, 2002) or synopticview (lower resolution but covering very large areas) digital data in three (red-greenblue) color bands.