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GOES I/M Imager

NSSDCA ID: 1994-022A-01

Mission Name: GOES 8


The GOES Imager is an advanced Earth imaging system on the GOES-NEXT (GOES I to M) series of geostationary meteorological satellites. The Imager will monitor changing weather patterns over the United States and provide imagery throughout the 24-hour day to assist weather forecasters. The GOES Imager consists of 5 spectral channels: 1 visible and four infrared (including a water vapor channel). The visible channel (0.55-0.75 micron) has a resolution of 1 square kilometer at nadir. The infrared channels (3.9, 10.7, and 12.0 microns) have ground resolutions of 4 square kilometers. The water vapor channel (6.7 microns) has a ground resolution of 8 square kilometers. The Imager optical system splits the scene radiation into 5 spectral bands by dichroic beamsplitters and registers the channels to permit simultaneous viewing of the same scene. The Imager telescope is an f/12.25 Cassegrain with a focal length of 381 cm. The four infrared channel detectors are located within a passive radiative cooler (which is thermally isolated from the rest of the sensor) and the visible detector is located on the aft optics subassembly. The visible detector is an 8 element array. Each IR channel has two active detectors for redundancy except the 6.7 micron channel which has one active and one redundant detector. The detectors convert the radiation into electrical signals which are directed through a preamplifier, a postamplifier, filters, and a 10-bit Analog-to-Digital Converter. All channels are sampled simultaneously by a sample and hold circuit and then stored in registers and read serially to the GOES data transmission system. All of the channels sweep a swath of 8 km as the mirror scans East to West or West to East. The GOES Imager uses an inductosyn as the servo error generator to compensate for spacecraft and orbit induced errors. The instrument channel-to-channel registration is within +/- 1 km. The Earth rectangle swath from 60 North to 60 South is imaged in 25 minutes or less with three images possible in 1.25 hours. Any 3000 x 3000 km area can be imaged within 5 minutes or less. Areas as small as 1000 x 1000 km can be obtained in two mintes or less. The GOES Imager will take no more then 3 minutes between the time a pixel is sensed and transmitted to users. The GOES Imager provides information on cloud imaging, snow and ice cover, low clouds and fog at night, cloud/snow discrimination, convection and synoptic analysis, cloud top temperatures, sea surface temperatures, and volcanic activity and forest fire detection. The GOES Imager produces images in either full disk, partial full disk or sectorized format in two basic formats: GOES projection for transmission on the GOES-TAP telephone line system and remapped imagery available (mid-1990's) to the National Weather Service (NWS) Advanced Weather Interactive Processing System (AWIPS-90). Most users will be able to obtain GOES-I images through GOES-TAP, Weather Facsimile (WEFAX) transmission, Global Telecommunications System (GTS), or through the NOAA/NESDIS Satellite Data Services Division.

Alternate Names

  • GOES8/GOESI/MImager

Facts in Brief

Mass: 119.5 kg
Power (avg): 134 W
Bit rate (avg): 2620.8 kbps

Funding Agencies

  • NASA-Office of Space Science Applications (United States)
  • NOAA National Environmental Satellite Service (United States)


  • Earth Science: Atmospheric Dynamics
  • Earth Science: Land Surface Processes

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



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