This is a cool application of GPS radio occultation. For a simple overview, see: http://www.atmo.arizona.edu/~kursinsk/GPS_RO_overview.htm http://www.atmo.ari

This is a cool application of GPS radio occultation. For a simple overview, see: http://www.atmo.arizona.edu/~kursinsk/GPS_RO_overview.htm http://www.atmo.arizona.edu/~kursinsk/GPS_RO_overview.htm The same idea has recently been used to improve weather forecasts for a few years now (http://en.wikipedia.org/wiki/GPS_meteorology http://en.wikipedia.org/wiki/GPS_meteorology). Differences in atmospheric gas density affect the propagation speed of the GPS radio signal. Peering thru the edge of the atmosphere at the constellation of GPS transmitters allows you to get a bunch of density/temperature profiles in a way that's immune to some instrumental artifacts of other instruments. One of the inventors of the idea formed a company to cooperatively launch small satellites to do these retrievals: http://geooptics.com/?page_id=35 http://geooptics.com/?page_id=35