POES is an acronym for Polar Operational Environmental Satellite. These are the successors to the TIROS satellites, and they are thus called the Advanced Television Infrared Observation Satellites (ATN or TIROS-N). Like the GOES, there are two POES operated by the U.S. Department of Defense’s Air Force Space and Missile System Center in what is called the Defense Meteorological Satellite Program. The POES orbit the Earth at elevations ranging from 515 to 540 miles (830 to 870 kilometers) in altitude, with one crossing the equator at 7:30 A.M. and 1:40 P.M. Data is then transmitted to stations located at Wallops Island, Virginia, and in Fairbanks, Alaska.