NOAA POES (Polar Orbiting Operational Environmental Satellite), USA
 




NOAA-17 was successfully launched on 24 June 2002

NOAA-POES is a series of polar orbiting environmental satelites operated by the US National Oceanographic and Atmospheric Administration (NOAA). It begins with the TIROS-N satellite in 1978. The NOAA-16 satellite(launched 21 Sep 2000) was declared the operational afternoon satellite on 20 March 2001, replacing NOAA-14 (launched 30 Dec 1994). Transmission of images from the AVHRR instrument on the NOAA-12 satellite (another afternoon satellite, launched 14 May 1991) is still available. It serves as a backup instrument for the operational AVHRR on NOAA-16. A new NOAA-17 satellite was launched on 24 June 2002. It is expected to be operational in late 2002.

The AVHRR instruments on NOAA-14 and 15 are functioning, but degraded. The NOAA-15 satellite was launched on 13 May 1998. After launch, the satellite experienced problems in deploying one of its antennas. Its imaging instrument failed in early July 2000. Beginning 20 March 2001, NOAA began to resynchronize the AVHRR on NOAA-15 once daily at 0730 UTC. During the time of the resynchronization, there is a very brief disruption on all data in the HRPT transmission. When the AVHRR is in synchronization, usable images may be obtained. When the AVHRR synchronization is out of limits, images are unusable.

The NOAA satellites provide at least four image acquisitions per day for any location on the earth. One of the main instruments carried on the satellites is the AVHRR (Advanced Very High Resolution Radiometer) for observation of clouds and land and sea surface at 1 km resolution in the visible and infrared wavelength regions. The earlier AVHRR instument on NOAA 9, 10, 11, 12 had 5 bands in the visible (band 1), NIR (band 2), MIR (band 3) and Thermal IR (bands 4, 5) regions. The newer AVHRR instrument starting from NOAA-14 has an extra band in the SWIR. This band shares the same transmission channel with the MWIR band which is designated Band 3A, while the SWIR band is Band 3B. Only one of the 3A or 3B bands is activated at any instant.

AVHRR data are acquired in three formats: High Resolution Picture Transmission (HRPT), Local Area Coverage (LAC), and Global Area Coverage (GAC). HRPT data are full resolution image data transmitted to a local ground station as they are being collected. LAC are also full resolution data, but recorded with an on-board tape recorder for subsequent transmission during a station overpass. GAC data provide daily subsampled global coverage recorded on the tape recorders and then transmitted to a ground station. Many weather stations around the world operate ground stations that routinely receive real-time HRPT data. LAC data are available from NOAA's Satellite Active Archive (SAA) through the world-wide web (http://www.saa.noaa.gov). Since on-board tape facility is limited, only a limited number of scenes are archived. GAC are subsampled on-board to about 4-km pixel separation at nadir for global fire monitoring. GAC data are also available from NOAA SAA.

NOAA Satellites Orbital Characteristics

  NOAA-12 NOAA-14 NOAA-15 NOAA-16
Launch date 14 May 1991 30 Dec 1994 13 May 1998 21 Sep 2000
Date operations began 17 Sep 1991 10 Apr 1995 15 Dec 1998 20 Mar 2001
Orbit inclination 98.5 99.1 98.6 98.8
Mean altitude (km) 808 847 810 851
Equator crossing time
(A: Northbound, B: Southbound)
16:49A, 04:49D 17:52A, 05:52D 19:08A, 07:08D 13:54A, 01:54D
Period (min.) 101.2 101.9 101.2 102.1

AVHRR Sensor Characteristics

Resolution1.1 km
Swath width3000 km

Band Wavelength (µm) Applications
Visible 1 0.58-0.68 cloud, snow and ice monitoring
Near IR 2 0.725-1.10 water, vegetation and agriculture surveys
Short Wave IR 3A 1.58-1.64snow, ice and cloud discrimination
Medium Wave IR 3B 3.55-3.93 sea surface temperature, volcano, forest fire activity
Thermal IR 4 10.3-11.3 sea surface temperature, soil moisture
Thermal IR 5 11.3-12.5 sea surface temperature, soil moisture



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Copyright CRISP, 2001