The Polar Operational Environmental Satellite (POES) project operates a constellation of weather satellites in polar orbits around the Earth. It is a joint effort between the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). Spacecraft for the project are provided by NASA and the European Space Agency. NASA's Goddard Space Flight Center oversees the manufacture, integration and test of the NASA-provided TIROS satellites. On-orbit satellite operation of these is performed by NOAA's Office of Satellite Operations (OSO). The POES constellation also includes an ESA-provided MetOp satellite operated by EUMETSAT.
Each POES satellite completes roughly 14.1 orbits per day. Since the number of orbits per day is not an integer, the ground tracks do not repeat on a daily basis. The systems includes both morning and afternoon satellites which provide global coverage four times daily.
Data from the POES satellites support a broad range of environmental monitoring applications including weather analysis and forecasting, climate research and prediction, global sea surface temperature measurements,