@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/52feba5f-c6cd-4d33-9eae-3660fecd5c02>
  ns0:altLabel [ ] ;
  skos:definition """[Source: National Space Science Data Center, http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1977-044A-04 ]

The instrument consisted of a high-frequency radio receiver connected to a short antenna that swept from 1.3 to 13.9 MHz in 100-kHz steps. The device was used to monitor the ionospheric breakthrough frequency of noise generated by manmade or natural sources below the f2 layer to obtain the critical frequency of this layer (fof2). The fof2 parameter was used in constructing electron-density profiles used in forecasting the state of the ionosphere. The instrument could detect electric fields down to 10 microvolts/m.


Group: Instrument_Details
   Entry_ID: PASSIVE IONOSPHERIC MONITOR
   Group: Instrument_Identification
      Instrument_Category: Solar/Space Observing Instruments
      Instrument_Class: Magnetic Field/Electric Field Instruments
      Short_Name: PASSIVE IONOSPHERIC MONITOR
      Long_Name: Passive Ionospheric Monitor (SSI/P)
   End_Group
   Group: Associated_Platforms
      Short_Name: DMSP 5D-1/F4
      Short_Name: DMSP 5D-1/F2
   End_Group
   Online_Resource: http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1977-044A-04
   Creation_Date: 2008-09-25
   Group: Instrument_Logistics
      Instrument_Owner: United States Air Force
   End_Group
End_Group"""@en ;
  skos:prefLabel "PASSIVE IONOSPHERIC MONITOR"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/bb175474-5e70-47be-8e1f-8dcd7563cc5b> ;
  a skos:Concept .

<https://gcmd.earthdata.nasa.gov/kms/concept/bb175474-5e70-47be-8e1f-8dcd7563cc5b>
  skos:prefLabel "Magnetic Field/Electric Field Instruments"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/52feba5f-c6cd-4d33-9eae-3660fecd5c02> .