{
  "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_2_2.xsd",
    "Version": "2.2.2",
    "Instrument": {
      "ResourceID": "spase://SMWG/Instrument/GIRO/Ionosonde",
      "ResourceHeader": {
        "ResourceName": "GIRO Ionospheric Sounder",
        "AlternateName": "Ionosonde",
        "ReleaseDate": "2012-03-21T09:08:00Z",
        "Description": "\n\nThe GIRO (Global Ionospheric Radio Observatory) comprises records of subpeak\nionospheric characteristics, including altitude profiles of electron \ndensity and plasma drift velocity, in the altitude range 90 km to the \npeak height of the F2 layer, measured by a global ground-based network \nof active high frequency (HF) radiowave remote sensing instruments, \nionosondes. The ionosonde uses stepped- or fixed-frequency probing \nradio signals transmitted from the ground for propagation into ionosphere, \ntotal reflection from an area of matching plasma density, and return to \nthe same or different ionosonde location for detection. The detected \nechoes are evaluated for their travel time and other characteristics \nsuch as amplitude, phase, polarization, Doppler frequency shift, and \nangle of arrival. The signal travel time is commonly translated to \nthe virtual range to the reflecting area in the ionosphere in the \nassumption of the signal propagating at the speed of light.\nStepped-frequency measurements provide adequate information to compute\ntrue range of reflections by accounting for refractive properties of plasma.\n\nThe ionosonde designs are commonly divided in two classes, (1) a pulsed sounder\nwith stepped frequency that transmits short pulses to detect the echo arrival\nin the time domain, and (2) a chirp-sounder that transmits a continuous\nswept-frequency signal to detect its reflections in the frequency domain.\nThe stepped- or swept-frequency sounders produce inherently 2-dimensional\ndata record (frequency x travel time), ionogram. Each element of the 2D\nionogram structure holds multiple signal characteristics measured in the\nionosonde's receiver channels. Thus acquired information is processed to\ndetect echoes and use their attributes to derive ionospheric characteristics\nalong the propagation path.\n\nThe fixed-frequency measurement, while using the same concept of radio\nsounding by total reflection, targets specific plasma densities in the \nionosphere, and usually provides higher Doppler frequency resolution by \ntransmitting pulses at the same frequency for several seconds. \nSimultaneously occurring reflection points in a structured ionosphere \nare identified by their different echo Doppler frequencies allowing the\ncomputation of Doppler skymaps and plasma drift velocity.\n      ",
        "Acknowledgement": "\nA heavy investment of time, effort, expertise, and \nfunds continues to be made to produce, collect, quality control, interpret, \nand store ionograms. It is important that data suppliers and the \nUML DIDBase developers are appropriately acknowledged in scientific \npublications that involve analysis of data obtained from the GIRO repositories\nsuch as DIDBase and DriftBase.\n      ",
        "Contact": [
          {
            "PersonID": "spase://SMWG/Person/Bodo.W.Reinisch",
            "Role": "PrincipalInvestigator"
          },
          {
            "PersonID": "spase://SMWG/Person/Ivan.A.Galkin",
            "Role": [
              "DataProducer",
              "TechnicalContact"
            ]
          }
        ],
        "InformationURL": {
          "Name": "GIRO (Global Ionospheric Radio Observatory) Home Page",
          "URL": "http://giro.uml.edu",
          "Description": "Access to real-time data and software tools",
          "Language": "en"
        },
        "Association": {
          "AssociationID": "spase://SMWG/Observatory/GIRO",
          "AssociationType": "Other"
        }
      },
      "InstrumentType": "Sounder",
      "InvestigationName": "Global Ionospheric Radio Observatory",
      "ObservatoryID": "spase://SMWG/Observatory/GIRO"
    }
  }
}