@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/0936ec9e-318d-4503-8e0b-4a2fa171c8fe>
  ns0:altLabel [ ] ;
  skos:definition """[Text Source: Paul A. Bernhardt 1, Craig A. Selcher 2, Santi Basu 3, Gary Bust 4 and Steven C Reising 5, "Atmospheric Studies with the Tri-Band Beacon Instrument on the COSMIC Constellation", TAO, Vol. 11, No. 1, 291-312, March 2000, http://www.engr.colostate.edu/ece/faculty/reising/pdf/.../ECEscr00010.pdf ]

The primary objective of the Tri-Band Beacon experiment on COSMIC is to study the electron density in the Earth's ionosphere. This is analyzing total electron content (TEC) data to produce electron densities as either two-dimensional maps or one-dimensional profiles. The earth's upper atmosphere contains a partially ionized plasma that is constantly changing under the influence of solar extreme ultraviolet (EUV) radiation, recombination chemistry, neutral winds, and electric fields (Rishbeth and Garriott, 1969; Kelley, 1989). The ionosphere extends from 50 km to above 1000-km altitude with variations in ion species balanced by equal densities of electrons. At altitudes below 150 km, the ions are primarily molecular. The peak densities are found in the F-layer near 300 to 400 km where atomic oxygen is the primary ion species. Above 1500-km altitude, the plasmasphere is composed of atomic hydrogen and helium ions along with an equal number of electrons to maintain neutrality. The atmospheric region known as the ionosphere is both important and complex. The ionosphere affects terres- trial radio signals. Satellite to ground links are affected by electron density irregularities that can degrade received signal strength. Communication, radar, and navigation systems often rely on predictions and measurements of ionospheric propagation conditions. Over-the-horizon radars require accurate models of the ionosphere to determine target locations 


Group: Instrument_Details
   Entry_ID: TBB
   Group: Instrument_Identification
      Instrument_Category: Earth Remote Sensing Instruments
      Instrument_Class: Active Remote Sensing
      Instrument_Type: Positioning/Navigation
      Short_Name: TBB
      Long_Name: Tri-Band Beacon
   End_Group
   Group: Associated_Platforms
      Short_Name: COSMIC/FORMOSAT-3
   End_Group
   Group: Spectral_Frequency_Information
      Wavelength_Keyword: Radio
      Spectral_Frequency_Coverage_Range: 150 MHz, 400 MHz, and 1067 MHz
   End_Group
   Online_Resource: http://www.google.com/url?sa=t&source=web&ct=res&cd=1&ved=0CA0QFjAA&url=http%3A%2F%2Fwww.engr.colostate.edu%2Fece%2Ffaculty%2Freising%2Fpdf%2Fjournals%2FECEscr00010.pdf&ei=xi3eSraQM4qN8Aa6tdVf&usg=AFQjCNG9STFHCXkqVEwNVL-WV8Aqos5Rnw&sig2=MxAFPQ7_Km6qBPWN2nbN0A
   Online_Resource: http://www.cosmic.ucar.edu/
   Online_Resource: http://cosmic-io.cosmic.ucar.edu/cdaac/
   Creation_Date: 2009-10-20
   Group: Instrument_Logistics
      Instrument_Owner: NSF/UCAR
   End_Group
End_Group"""@en ;
  skos:prefLabel "TBB"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/e87a9716-cf7e-42c7-8e70-a45e6ee337d2> ;
  a skos:Concept .

<https://gcmd.earthdata.nasa.gov/kms/concept/e87a9716-cf7e-42c7-8e70-a45e6ee337d2>
  skos:prefLabel "Positioning/Navigation"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/0936ec9e-318d-4503-8e0b-4a2fa171c8fe> .