[Text Source: NASA Spaceflight.com, "Atlas’ 600th Mission launches with DMSP F18 from Vandenberg", 2009-10-18, ... http://www.nasaspaceflight.com/2009/10/live-atlas-600th-mission-lau... ]
The Defense Meteorological Satellite Program F18 (DMSP F18) satellite will help the Air Force provide “strategic and tactical weather prediction … to aide the U.S. military in planning operations at sea, on land, and in the air,” notes the ULA mission over presentation.
Furthermore, “DMSP is a space- and ground-based system to collect and disseminate timely global environmental data to the Department of Defense and other governmental agencies.”
DMSP F18 will provide viable data on soil moisture, surface temperatures, and cloud cover around the globe via its multitude of onboard sensors and polar orbit.
The presentation goes on to discuss some specifics of the DMSP satellite system, of which F18 is a part. “DMSP satellites ’see’ environmental features such as clouds, bodies of water, snow, fire, and pollution in the visual and infrared spectra.”
The satellite system can monitor global water temperatures, cloud cover, water currents, and ocean surface characteristics during their 101-minute orbital period around Earth. This, coupled with their polar and “sun-synchronous” orbits, allows each DMSP weather satellite to monitor nearly the entire globe every six hours.
The data collected by the satellites is transmitted to the ground where a team of meteorologists interpret the data and disseminate the information for the U.S. military, which in turn uses the data to plan and conduct U.S. military operations around the globe.
In addition to DMSP F18, two more DMSP weather satellites are awaiting launch. These satellites are currently stored at Space Systems’ operations in Sunnyvale, California. They will be transported to Vandenberg upon the request of the Air Force for launch operations.