@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix ns0: <http://gcmd.gsfc.nasa.gov/kms#> .

<https://gcmd.earthdata.nasa.gov/kms/concept/b5e4912d-3224-4d7b-924c-a697677775c6>
  skos:prefLabel "Ultraviolet Instruments"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/f2fac046-d9cb-4012-8dce-a16d4724ef18> .

<https://gcmd.earthdata.nasa.gov/kms/concept/f2fac046-d9cb-4012-8dce-a16d4724ef18>
  ns0:altLabel [ ] ;
  skos:definition """The objectives of the Solar Backscatter Ultraviolet (SBUV) flown on
      NIMBUS-7 were to determine the vertical distribution of ozone, map the
      total ozone content, and monitor the incident solar ultraviolet (UV)
      irradiance and ultraviolet radiation backscattered from the earth. The
      SBUV consisted of a double Ebert-Fastie spectrometer and a filter
      photometer similar to the BUV on Nimbus 4. The SBUV spectrometer
      measured solar UV backscattered by the earth's atmosphere at 12
      wavelengths between 0.25 and 0.34 micrometer, with a spectral bandpass
      of 0.001 micrometer. The SBUV used three detectors: a photomultiplier
      tube (PMT) and a photodiode for the monochromator, and one photodiode
      for the photometer. Both the monochromator and the photometer have
      chopper wheels operating at 25 Hz.  The SBUV used a depolarizer to
      eliminate the sensitivity of the grating monochromator to polarization
      of the backscattered radiation. The instrument's field of view (FOV)
      at nadir was 0.20 rad. A roughened aluminum diffuser plate viewed the
      sun for solar-spectral irradiance measurements and for calibration by
      viewing a mercury-argon lamp. The diffuser plate was driven by a
      stepper motor to three postions on command: SBUV, TOMS, and STOW. The
      contribution functions for the eight shortest wavelengths were
      centered at levels ranging from 55 to 28 km and were used to infer the
      vertical ozone profile. The four longest wavelengths had contribution
      functions in the troposphere which were used to compute the total
      ozone amount. The SBUV spectrometer had a second mode of operation
      that allowed a continuous solar-spectral scan from 0.16 to 0.4
      micrometer for detailed examination of the extraterrestrial solar
      spectrum and its temporal variations. A parallel photometer channel at
      0.343 micrometer measured the reflectivity of the atmosphere's lower
      boundary in the same 0.21-rad FOV.
      A another version of the SBUV (SBUV/2) has been flown on the NOAA
      Polar Orbiting series of spacecraft on NOAA-9, NOAA-11, and NOAA-14.m
      The SBUV/2 was a non-scanning, nadir viewing instrument designed to
      measure scene radiance in the spectral region from 160 to 400 nm. SBUV
      data are used to determine the vertical distribution of and total
      ozone in the atmosphere, and solar spectral irradiance.

      Additional Information:

SBUV sensor: "http://www.eumetsat.de/en/index.html?area=left2.html&body
=/en/area2/cgms/ap10-12.htm&a=284&b=2&c=280&d=200&e=0"

      TOMS: "http://jwocky.gsfc.nasa.gov/\""""@en ;
  skos:prefLabel "SBUV"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/b5e4912d-3224-4d7b-924c-a697677775c6> ;
  a skos:Concept .