@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/73f8e476-b048-4f4d-b350-8987e3862e45>
  ns0:altLabel [ ] ;
  skos:definition """Sudden Ionospheric Disturbance Stations (SID) consists of solar observers who monitor very low frequency (VLF) radio stations for sudden enhancements of their signals. Earth's ionosphere reacts to the intense x-ray and ultraviolet radiation released during a solar flare. The ionospheric disturbance enhances VLF radio propagation. By monitoring the signal strength of a distant VLF transmitter, sudden ionospheric disturbances (SIDs) are recorded and indicate a recent solar flare event.

All SID monitoring stations are homebuilt by the observers. Instructions for constructing the VLF receiver and antenna can be obtained from the AAVSO Solar Division chairman. The receiver design has progressed remarkably as the SID program participants have been inspired to improve signal sensitivity and noise rejection. Recent SID station receivers follow a design developed by SID Technical Coordinator Art Stokes. The Stokes Gyrator receiver can be built and tuned by anyone with simple soldering skills. A small indoor loop antenna captures the radio wave for amplification and rectification by the receiver. The SID station operates unattended until the end of each month. Recordings are then analyzed for the beginning, end, and duration of SID events.

More info available at
http://www.aavso.org/committees/solar/sid.stm

[Source: AAVSO]


Group: Platform_Details
   Entry_ID: SID
   Group: Platform_Identification
      Platform_Category: In Situ Land-based Platforms
      Platform_Series_or_Entity: SOLAR/SPACE MONITORING STATIONS
      Short_Name: SID
      Long_Name: Sudden Ionospheric Disturbance Stations
   End_Group
   Group: Synonymous_Platform_Names
      Short_Name: SID
   End_Group
   Creation_Date: 2007-12-10
   Online_Resource: http://www.aavso.org/committees/solar/sid.stm
End_Group"""@en ;
  skos:prefLabel "SID"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/platforms> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/a143e5f5-4e4c-45cb-8053-5c9f6a099784> ;
  a skos:Concept .

<https://gcmd.earthdata.nasa.gov/kms/concept/a143e5f5-4e4c-45cb-8053-5c9f6a099784>
  skos:prefLabel "SOLAR/SPACE MONITORING STATIONS"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/73f8e476-b048-4f4d-b350-8987e3862e45> .