{
  "Spase": {
    "xmlns": "http://www.spase-group.org/data/schema",
    "xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance",
    "xsi:schemaLocation": "http://www.spase-group.org/data/schema http://www.spase-group.org/data/schema/spase-2_3_2.xsd",
    "Version": "2.3.2",
    "NumericalData": {
      "ResourceID": "spase://ASWS/NumericalData/Ionospheric_Scintillation_Monitor/Vnm_Ionospheric_Scintillation_Monitor",
      "ResourceHeader": {
        "ResourceName": "Australian Space Weather Services Vanimo Ionospheric Scintillation Monitor",
        "ReleaseDate": "2021-03-29T17:14:50Z",
        "Description": "\r\n\t  Ionospheric scintillation is a rapid fluctuation of radio-frequency signal phase and/or amplitude, generated as a signal passes through the ionosphere. Scintillation occurs when a radio frequency signal in the form of a plane wave traverses a region of small scale irregularities in electron density. The irregularities cause small-scale fluctuations in refractive index and subsequent differential diffraction (scattering) of the plane wave producing phase variations along the phase front of the signal. As the signal propagation continues after passing through the region of irregularities, phase and amplitude scintillation develops through interference of multiple scattered signals. The first Ionospheric Scintillation Monitor in Vanimo was installed in 20/08/1999 and closed on 01/07/2009. \r\n      ",
        "Acknowledgement": "We are thankful to the Space Weather Network, Bureau of Meteorology of Australia for the observations of Vanimo Ionospheric Scintillation Monitor data.",
        "Contact": [
          {
            "PersonID": "spase://ASWS/Person/Kehe.Wang",
            "Role": "GeneralContact"
          },
          {
            "PersonID": "spase://ASWS/Person/Kehe.Wang",
            "Role": "MetadataContact"
          }
        ],
        "InformationURL": {
          "Name": "Documentation",
          "URL": "https://www.sws.bom.gov.au/World_Data_Centre/2/6/",
          "Description": "includes descriptions of station logfiles, data formats and examples and hardware",
          "Language": "en"
        }
      },
      "AccessInformation": {
        "RepositoryID": "spase://SMWG/Repository/SWS",
        "Availability": "Online",
        "AccessRights": "Open",
        "AccessURL": [
          {
            "Name": "World Data Centre: Data Display and Download: Ionospheric Scintillation Monitor",
            "URL": "https://www.sws.bom.gov.au/World_Data_Centre/1/11",
            "Style": "Search",
            "Description": "includes browse display interface, button to get daily data file and link to data availability chart",
            "Language": "en"
          },
          {
            "Name": "Real Time Information",
            "URL": "https://www.sws.bom.gov.au/Satellite/1/1",
            "Style": "Overview",
            "Description": "Online viewer of real time Ionospheric Scintillation Monitor data, Latest Conditions, Regional Map, Recent Scintillation Events.",
            "Language": "en"
          },
          {
            "Name": "Access to Ionospheric Scintillation Monitor data (not with most browsers)",
            "URL": "https://downloads.sws.bom.gov.au/wdc/wdc_ism/data/vanimo/",
            "Style": "Listing",
            "Description": "Access to the station Ionospheric Scintillation Monitor data data of Vanimo.",
            "Language": "en"
          }
        ],
        "Format": "Text",
        "Encoding": "None"
      },
      "ProviderProcessingLevel": "The Ionospheric Scintillation Monitor data are processed data and are uncalibrated.",
      "InstrumentID": "spase://ASWS/Instrument/Ground/Vanimo/Ionospheric_Scintillation_Monitor",
      "MeasurementType": "Waves.Active",
      "TemporalDescription": {
        "TimeSpan": {
          "StartDate": "1999-08-20T00:00:00Z",
          "RelativeStopDate": "-P1D",
          "Note": "The earliest Ionospheric Scintillation Monitor data since 20/08/1999. Digital data are current to within a day."
        }
      },
      "ObservedRegion": "Earth.NearSurface.Ionosphere",
      "Keyword": [
        "Ionospheric Scintillation Monitor",
        "ISM",
        "GPS",
        "Ionosphere"
      ],
      "Parameter": [
        {
          "Name": "S4 Final",
          "Description": "S4 is a dimensionless number with a theoretical upper limit of 1.0, commonly estimated over an interval of 60 seconds.\r\nThere are two defined regimes of amplitude scintillation: weak and strong, which roughly correspond to the type of scattering associated with each. Strong scintillation is generally considered to occur when S4 is greater than ~0.6 and is associated with strong scattering of the signal in the ionosphere. Below this is weak scintillation. An S4 level below 0.3 is unlikely to have a significant impact on GPS.",
          "Cadence": "PT60S",
          "Units": "S4 Final (Ionospheric Amplitude Scintillation Index)",
          "ValidMin": "0.000000",
          "ValidMax": "1.000000",
          "Field": {
            "FieldQuantity": "Electromagnetic"
          }
        },
        {
          "Name": "Sigma60",
          "Description": "Phase scintillation is quantified by the Prms (or Φrms) index which is defined as the standard deviation of the signal phase over a given time interval. This index is measured either in radians or degrees. A Prms greater than ~ 1° is considered to be strong scintillation. At mid-latitudes, Prms rarely exceeds 1° for more than 1% of the time.",
          "Cadence": "PT60S",
          "Units": "Sigma60 (Ionospheric Phase Scintillation Index)",
          "ValidMin": "0.000000",
          "ValidMax": "1.000000",
          "Field": {
            "FieldQuantity": "Electromagnetic"
          }
        }
      ]
    }
  }
}