Understanding the atmosphere through radio occultation:Second FORMOSAT-3/COSMIC Data Users Workshop; Boulder, Colorado, 22 - 24 October 2007

COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) is a joint Taiwan/U.S. mission consisting of six microsatellites, each carrying a Global Positioning System (GPS) receiver, a tri-band beacon to sense free electrons in the ionosphere via radio waves, and a Tiny Ionospheric Photometer to map ionospheric electron density via ultraviolet emission.

The primary purpose of COSMIC is to demonstrate the value of radio occultation (RO) observations of the atmosphere to weather prediction, climate, and space weather. The RO technique produces a vertical profile of refractivity versus height in the ionosphere, stratosphere, and troposphere. This allows scientists to deduce valuable information on electron density, temperature, and water vapor in the atmosphere.