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Scanning Radiometer (SR)

NSSDCA ID: 1970-012A-01

Mission Name: DMSP 5A/F1
Principal Investigator:

Description

The three-channel scanning radiometer, designated the sensor AVE (Aerospace Vehicle Electronics) package (SAP), was the primary experiment on the DMSP spacecraft. The purpose of this experiment was to provide global, day/night observations of cloudcover and cloud temperature measurements to support Department of Defense requirements for operational weather analysis and forecasting. The radiometer operated in two spectral intervals -- (1) visible and near infrared (0.4 to 1.1 micrometer) and (2) infrared (8 to 13 micrometer). The three-channel radiometer was essentially two scanning radiometers driven by a common motor. One radiometer provided high resolution (HR) visual and infrared (IR) data with nadir resolutions of 3.7 and 4.4 km, respectively. The other radiometer produced very high resolution (VHR) visual data with nadir resolutions of .63 km. Onboard recorders had a storage capacity of 210 min of both HR and IR data and a total of 20 min of VHR data. For direct readout to tactical sites, the experiment was programmed so that VHR and IR data were obtained during the daytime and HR and IR data were obtained at night. The infrared channel covered a temperature range of 210 to 310 deg k with an accuracy of 1 deg c. Electronic circuitry in the sensor converted the sensed infrared energy directly into equivalent black body temperature (as opposed to radiance) prior to transmission to ground sites. The HR channel included a zero resolution sensor which measured solar input and was used to control channel gain, thereby producing an output signal that represents scene albedo. This feature also made it possible to obtain useful visual data at night. The sensor incorporated sunshades and glare suppression devices in conjunction with a long-scan automatic gain control which allowed the HR channel to provide usable data through the day/night terminator. Identical experiments were flown on all DMSP Block 5 spacecraft launched prior to April 1972.

Alternate Names

  • DMSP5A-F1/SR
  • SR

Funding Agency

  • Department of Defense-Department of the Air Force (United States)

Discipline

  • Earth Science: Atmospheric Dynamics

Additional Information

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

 

Personnel

NameRoleOriginal AffiliationE-mail
Principal InvestigatorGlobal Weather Center
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