{
    "identifier": "gov.noaa.ncdc:C01371",
    "accessLevel": "public",
    "contactPoint": {
        "@type": "vcard:Contact",
        "fn": "Your contact point",
        "hasEmail": "mailto:[email protected]"
    },
    "programCode": [
        "010:000"
    ],
    "landingPage": "",
    "title": "MetOp Series Global Navigation Satellite System Receiver for Atmospheric Sounding (GRAS) Level 1B Data",
    "description": "The Global navigation satellite system Receiver for Atmospheric Sounding (GRAS) is a radio occultation receiver onboard the European MetOp satellite series. GRAS uses radio occultation to measure vertical profiles of atmospheric temperature and humidity by tracking signals received from a constellation of GNSS satellites. As radio waves pass through the atmosphere, they are refracted along the atmospheric path. The degree of refraction depends on gradients of air density, which in turn depend on temperature and water vapor. Therefore, measurement of the refracted angle contains information about these atmospheric variables. Since the measurements are made tangentially to the atmosphere, the profiles will be provided with a resolution within a few hundred meters to 1.5 kilometers. GRAS provides 500 precise atmospheric profiles every day, nearly equally distributed over the Earth's surface. GRAS can track up to eight satellites for navigation purposes and two additional satellites for both rise and set occultation measurements. The GRAS Level 1b product contains profiles of the bending angle over impact parameter and auxiliary information. GRAS Level-1b products are produced by the European Organization for Meteorological Satellites (EUMETSAT) and distributed by NOAA's Comprehensive Large Array-Data Stewardship System (CLASS) in the EPS Native Format.",
    "language": "",
    "distribution": [
        {
            "@type": "dcat:Distribution",
            "mediaType": "application\/json",
            "accessURL": "https:\/\/www.ncei.noaa.gov\/metadata\/geoportal\/\/rest\/metadata\/item\/gov.noaa.ncdc%3AC01371"
        },
        {
            "@type": "dcat:Distribution",
            "mediaType": "text\/html",
            "accessURL": "https:\/\/www.ncei.noaa.gov\/metadata\/geoportal\/\/rest\/metadata\/item\/gov.noaa.ncdc%3AC01371\/html"
        },
        {
            "@type": "dcat:Distribution",
            "mediaType": "application\/xml",
            "accessURL": "https:\/\/www.ncei.noaa.gov\/metadata\/geoportal\/\/rest\/metadata\/item\/gov.noaa.ncdc%3AC01371\/xml"
        }
    ],
    "bureauCode": [
        "010:04"
    ],
    "modified": "2025-11-19T15:30:19.481Z",
    "publisher": {
        "@type": "org:Organization",
        "name": "Your Publisher"
    },
    "theme": "",
    "keyword": [
        "Earth Science > Spectral\/Engineering > Radio Wave",
        "Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles",
        "Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature",
        "Vertical Location > Troposphere",
        "Vertical Location > Stratosphere",
        "NOAA OneStop",
        "GRAS > Global navigation satellite system Receiver for Atmospheric Sounding",
        "METOP-A > Meteorological Operational Satellite - A",
        "METOP-B > Meteorological Operational Satellite - B",
        "METOP-C > Meteorological Operational Satellite - C",
        "gov.noaa.class:GRAS",
        "climatologyMeteorologyAtmosphere"
    ]
}