{
  "Spase": {
    "xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance",
    "xmlns": "http://www.spase-group.org/data/schema",
    "xsi:schemaLocation": "http://www.spase-group.org/data/schema http://www.spase-group.org/data/schema/spase-2_1_0.xsd",
    "Version": "2.1.0",
    "Instrument": {
      "ResourceID": "spase://SMWG/Instrument/ISIS2/SFS",
      "ResourceHeader": {
        "ResourceName": "ISIS2 Swept-Frequency Sounder",
        "AlternateName": "Topside Sounder",
        "ReleaseDate": "2019-05-05T12:34:56Z",
        "Description": "The ISIS 2 (International Satellites for Ionospheric Studies) Swept-Frequency Sounder measured the ionospheric electron density in the altitude range 300 to 1400 km, and provided  correlative data for the other ISIS 2 experiments, particularly those measuring ionospheric parameters. The ionosonde was a radio transmitter that recorded the time delay between a transmitted and returned radio-frequency pulse. A continuum of frequencies between 0.1 and 20 MHz was sampled every 14 or 21 s, and one of six selected frequencies was also used for sounding for a few seconds during each 14- or 21-s period. In addition to the sweep- and fixed-frequency modes of operation, a mixed mode was available in which the transmitter frequency was fixed at one of six possible frequencies while the receiver swept. Several virtual-range (delay-time) traces resulting from ground reflections, plasma resonances, birefringence of the ionosphere, nonvertical propagation, etc., were normally observed.",
        "Contact": {
          "PersonID": "spase://SMWG/Person/James.H.Whitteker",
          "Role": "PrincipalInvestigator"
        },
        "InformationURL": {
          "Name": "NSSDC's Master Catalog",
          "URL": "https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1971-024A-01",
          "Description": "Information about the Swept-Frequency Sounder on ISIS 2"
        }
      },
      "InstrumentType": "Sounder",
      "InvestigationName": "Swept-Frequency Sounder on ISIS 2",
      "ObservatoryID": "spase://SMWG/Observatory/ISIS2"
    }
  }
}