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

<https://gcmd.earthdata.nasa.gov/kms/concept/79db06d1-7b80-4f8d-8466-ac7cbed4926a>
  ns0:altLabel [ ] ;
  skos:definition """The Fourier Transform Spectrometer (ACE-FTS)

      Background

      The Fourier Transform Spectrometer (ACE-FTS) is the primary
      instrument selected for the Atmospheric Chemistry Experiment
      (ACE) mission onboard the SCISAT satellite. A second instrument,
      Measurements of Aerosol Extinction in the Stratosphere and
      Troposphere Retrieved by Occultation (MAESTRO), is also onboard
      SCISAT.

      The ACE-FTS was built in co-operation with the Canadian Space
      Agency by ABB Bomem of Qu?bec City. Funding for the ACE mission,
      including both Canadian instruments, was provided by the
      Canadian Space Agency?s Space Science Program.

      How ACE-FTS functions

      The ACE-FTS instrument is designed to simultaneously measure the
      temperature, trace gases, thin clouds, and aerosols found in the
      atmosphere using a solar occultation technique. For this
      technique to work, the orbiting satellite must first point to
      the Earth's horizon during sunrise or sunset. As the sun "moves"
      through the thin band of atmosphere at the horizon, its rays are
      partly absorbed by the various gases in the atmosphere at
      different altitudes. It is these gases and their distribution
      that the high-resolution, infrared ACE-FTS will measure. Thus,
      as the instrument observes the rising or setting sun, it can
      perform its measurements throughout the whole thickness of the
      atmosphere. Aerosols such as those caused by gases ejected by
      volcanoes will also be measured.

      SCISAT?s low orbit of 650 km above the Earth will give the
      ACE-FTS instrument extensive coverage with an emphasis on
      mid-latitude areas, such as Canada and the United States, as
      well as the polar region. The area to be scanned will be from
      about 4 km above the cloud tops (or the boundary layer for clear
      scenes) up to about 100 km. SCISAT will orbit the Earth 15 times
      a day, providing 30 daily opportunities (sunrises and sunsets)
      to take its precise measurements.

      Complements other experiments

      ACE-FTS will measure the density of a large number of chemicals
      in order to make an accurate estimate of both chemical loss and
      the movement of ozone in the polar winter and springtime. Its
      results will be complemented by those gathered by MAESTRO. The
      overall ACE mission will work in conjunction with other
      instruments and missions planned by NASA, the European Space
      Agency, and other international partners over the next decade to
      gain a better understanding of the chemistry and dynamics of the
      stratosphere with an emphasis on ozone.

      View the SCISAT homepage at:
      "http://www.space.gc.ca/asc/eng/csa_sectors/space_science/atmospheric/
scisat/scisat.asp"

      [Summary provided by the Canadian Space Agency]"""@en ;
  skos:prefLabel "ACE-FTS"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/055a79c7-61db-4250-abad-f1e09909f14c> ;
  a skos:Concept .

<https://gcmd.earthdata.nasa.gov/kms/concept/055a79c7-61db-4250-abad-f1e09909f14c>
  skos:prefLabel "Spectrometers"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/79db06d1-7b80-4f8d-8466-ac7cbed4926a> .

