{
  "Spase": {
    "xmlns": "http://www.spase-group.org/data/schema",
    "xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance",
    "xsi:schemaLocation": "https://www.spase-group.org/data/schema  https://www.spase-group.org/data/schema/spase-2.7.1.xsd",
    "Version": "2.7.1",
    "MetadataRightsList": {
      "Rights": {
        "SchemeURI": "https://spdx.org/licenses/",
        "RightsIdentifierScheme": "SPDX",
        "RightsIdentifier": "CC0-1.0",
        "RightsURI": "https://spdx.org/licenses/CC0-1.0.html",
        "RightsName": "Creative Commons Zero v1.0 Universal",
        "Note": "CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions"
      }
    },
    "NumericalData": {
      "ResourceID": "spase://NASA/NumericalData/SDO/HMI/Linewidth_Data/PT720S",
      "NamingAuthority": "NASA",
      "ResourceType": "NumericalData",
      "ResourceHeader": {
        "ResourceName": "SDO/HMI Linewidth, 720-Second Data",
        "DOI": "https://doi.org/10.48322/v6me-8w52",
        "ReleaseDate": "2025-12-04T13:31:26Z",
        "RevisionHistory": {
          "RevisionEvent": [
            {
              "ReleaseDate": "2024-11-01T00:08:46",
              "Note": "Metadata created by SY"
            },
            {
              "ReleaseDate": "2024-11-18T00:08:46",
              "Note": "Added DOI by SY"
            },
            {
              "ReleaseDate": "2025-09-18T11:27:08Z",
              "Note": "Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB"
            },
            {
              "ReleaseDate": "2025-09-30T14:25:17Z",
              "Note": "Updated PublishedBy name to match ROR Registry. ZCB"
            },
            {
              "ReleaseDate": "2025-12-04T13:31:26Z",
              "Note": "Added MetadataRightsList. Updated to 2.7.1. ZCB"
            }
          ]
        },
        "Description": "The linewidth observable refers to the FWHM of the (assumed) Gaussian absorption line profile for the 6173.3 Å line on the surface of the sun.\n\nHMI samples the Fe I absorption line at 6173.3 Å at six points. Assuming that the \"pure\" solar Fe I line profile is a Gaussian, and the HMI filter filter transmission profiles are delta functions, the first and second Fourier coefficients of the of the Fe I line can be calculated and an estimate of the Doppler Velocity can be made. An estimate (proxy) for the continuum intensity Ic is obtained by \"reconstructing\" the solar line from the estimates of the Doppler shift λo, the linewidth σ, and the linedepth Id. More details can be found at http://jsoc.stanford.edu/relevant_papers/observables.pdf.",
        "PublicationInfo": {
          "Authors": "The HMI Consortium: Stanford University (USA); NASA Goddard Space Flight Center (USA); Lockheed Martin Solar and Astrophysics Laboratory (USA); National Center for Atmospheric Research (USA)",
          "PublicationDate": "2011-01-21T00:00:00",
          "PublishedBy": "Stanford University"
        },
        "Contact": [
          {
            "PersonID": "spase://SMWG/Person/Philip.H.Scherrer",
            "Role": "PrincipalInvestigator"
          },
          {
            "PersonID": "spase://SMWG/Person/Rick.Bogart",
            "Role": "GeneralContact"
          }
        ],
        "InformationURL": [
          {
            "Name": "The HMI website at Stanford",
            "URL": "http://hmi.stanford.edu/"
          },
          {
            "Name": "The SDO/HMI Instrument paper",
            "URL": "https://doi.org/10.1007/s11207-011-9834-2"
          }
        ]
      },
      "AccessInformation": {
        "RepositoryID": "spase://SMWG/Repository/Stanford/HMI-AIA.JSOC",
        "Availability": "Online",
        "AccessRights": "Open",
        "AccessURL": [
          {
            "Name": "JSOC Data Center",
            "URL": "http://jsoc.stanford.edu/ajax/lookdata.html?ds=hmi.Lw_720s[2020-01-01T00:00:00/60m]",
            "Style": "Search",
            "Description": "Change the date and the time to find the HMI data."
          },
          {
            "Name": "SDO/HMI Data Search via Virtual Solar Observatory",
            "URL": "https://sdac.virtualsolar.org/cgi/search?time=1&instrument=HMI&spectrum=1&version=current&build=1",
            "Description": "VSO path to JSOC-resident SDO HMI data files"
          }
        ],
        "Format": "FITS"
      },
      "InstrumentID": "spase://SMWG/Instrument/SDO/HMI",
      "MeasurementType": "ImageIntensity",
      "TemporalDescription": {
        "TimeSpan": {
          "StartDate": "2010-04-24T19:11:26",
          "RelativeStopDate": "-P3D"
        },
        "Cadence": "PT720S"
      },
      "ObservedRegion": [
        "Sun",
        "Sun.Photosphere"
      ],
      "Parameter": {
        "Name": "FITS Data Array",
        "Description": "Linewidth",
        "Cadence": "PT720S",
        "CoordinateSystem": {
          "CoordinateRepresentation": "Cartesian",
          "CoordinateSystemName": "HPC"
        },
        "Wave": {
          "WaveType": "Photon",
          "WaveQuantity": "Wavelength",
          "WavelengthRange": {
            "Low": "6173",
            "High": "6173",
            "Units": "angstrom"
          }
        },
        "SpatialCoverage": {
          "CoordinateSystem": {
            "CoordinateRepresentation": "Cartesian",
            "CoordinateSystemName": "HPC"
          },
          "Description": "Array size: 4096x4096\nPixel Resolution: 0.504 arcsec"
        }
      }
    }
  }
}