NOAA Polar-orbiting Operational Environmental Satellites (POES) Radiometer Data

The Polar-orbiting Operational Environmental Satellite (POES) series offers the advantage of daily global coverage, by making nearly polar orbits 14 times per day approximately 520 miles above the surface of the Earth. The Earth's rotation allows the satellite to see a different view with each orbit, and each satellite provides two complete views of a location around the world each day. The POES constellation of weather satellites is a joint effort between the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The Advanced Very High Resolution Radiometer (AVHRR) is a cross-track scanning system with five spectral bands having a resolution of 1.1 km and a frequency of earth scans twice per day (usually 0230 and 1430 local solar time) on NOAA and EUMETSAT satellites. There are three data types produced from the NOAA POES AVHRR. The Global Area Coverage (GAC) data set is reduced resolution image data that is processed onboard the satellite taking only one line out of every three and averaging every four of five adjacent samples along the scan line; the Local Area Coverage (LAC) data set is recorded onboard at original resolution (1.1 km) for part of an orbit and later transmitted to earth; and the High Resolution Picture Transmission (HRPT) is real-time downlink data. The EUMETSAT MetOp satellite series, initially launched on October 19, 2006, produces the same three data types as well as a fourth data type, Global Full Resolution Area Coverage (FRAC 1.1 km). The MetOp polar orbiting operational meteorological satellite system is the European contribution to the Initial Joint Polar-Orbiting Operational Satellite System (IJPS). AVHRR data provide opportunities for studying and monitoring vegetation conditions in ecosystems including forests, tundra and grasslands. Applications include agricultural assessment, land cover mapping, producing image maps of large areas such as countries or continents, and tracking regional and continental snow cover. AVHRR data are also used to retrieve various geophysical parameters such as sea surface temperatures and energy budget data.