@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix org: <http://www.w3.org/ns/org#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0> a dcat:Dataset ;
    dct:description "These Ionograms were digitized from the original ISIS-2 7-Track Analog Telemetry Tapes using the Facilities of the former Data Evaluation Laboratory at the NASA/GSFC. This Data Restoration Project is headed by Dr. R.F. Benson (NASA/GSFC). Ionograms were digitized at the Rate of 40,000 16-bit samples/s. This Sample Rate is higher than the Nyquist Frequency of 30 kHz. The Sample Frequency of 40 kHz provides a Measurement every 25 µs corresponding to an Apparent Range Interval equal to 3.75 km from c*t/2, where c is the Speed of Light. Ionograms with this Sample Rate are designated as 'Full' Ionograms because they have the full 3.75 km Apparent-Range Resolution. The Ionograms used for most Analyses, and those available from CDAWeb, were produced by averaging every four Samples of the Sounder-Receiver Video Amplitude Output to yield an average Value every 100 µs corresponding to an Apparent-Range Resolution of 15 km. These Ionogram Files are referred to as 'Average' Files with Standard Resolution. Each Ionogram consists of a Fixed-Frequency Portion and a Swept-Frequency Portion. The Time Resolution between Ionograms is typically 14 or 22 s depending on the Frequency Sweep Range." ;
    dct:identifier <https://doi.org/10.48322/5h5w-fq61> ;
    dct:issued "2026-08-10T19:03:09.614260"^^xsd:dateTime ;
    dct:modified "2026-11-02T22:16:01+00:00"^^xsd:dateTime ;
    dct:publisher <https://data.nasa.gov/organization/dbb294e4-8597-44f5-aaf4-c0baac12cdbc> ;
    dct:title "ISIS-2 Topside Sounder Average Ionogram over Ascension Island, United Kingdom: ACN, Latitude -8, Longitude 346" ;
    dcat:contactPoint [ a vcard:Organization ;
            vcard:fn "NASA Space Physics Data Facility" ;
            vcard:hasEmail <mailto:NASA-SPDF-Support@nasa.onmicrosoft.com> ] ;
    dcat:distribution <https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/22d0aa76-2cd6-4f0d-9c8d-d62c0c7b6d5a>,
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        <https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/62fcc30a-b948-4455-a3a4-112c38384eb1>,
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        <https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/cfd1abf3-daac-4ed0-8dc2-890ba94016cb> ;
    dcat:keyword "auroral-kilometric-radiation-akr",
        "ducted-echoes",
        "field-aligned-irregularities-fai",
        "ground-echoes",
        "ground-reflections",
        "ionogram",
        "ionospheric-echoes",
        "ionospheric-reflections",
        "plasma-resonance",
        "plasma-waves",
        "solar-type-iii-bursts",
        "spectrum",
        "swept-frequency-sounder",
        "topside-ionosphere",
        "topside-sounder",
        "upper-hybrid-noise-band",
        "wave-scattering",
        "waves-active" ;
    dcat:theme <%7BHeliophysics%7D> .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/22d0aa76-2cd6-4f0d-9c8d-d62c0c7b6d5a> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.586069"^^xsd:dateTime ;
    dcat:accessURL <https://helio.data.nasa.gov/dataset/ISIS2_SFS_AverageIonogram_AscensionIsland_PT22S> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/36ebe2f9-e10f-4466-a52c-e579e4e5cb6b> a dcat:Distribution ;
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    dcat:accessURL <https://cdaweb.gsfc.nasa.gov/index.html/> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/41eda56b-b04f-4067-bfaa-a2114b5fe0df> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.585434"^^xsd:dateTime ;
    dcat:accessURL <https://cdaweb.gsfc.nasa.gov/hapi> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/566e0457-bf8f-4150-9d49-be4a2a0671e6> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.585884"^^xsd:dateTime ;
    dcat:accessURL <https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-009A> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/62fcc30a-b948-4455-a3a4-112c38384eb1> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.586250"^^xsd:dateTime ;
    dcat:accessURL <https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/AscensionIsland/PT22S> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/74866d30-e65d-4b6f-9bd5-bdc613428cdb> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.585025"^^xsd:dateTime ;
    dcat:accessURL <https://spdf.gsfc.nasa.gov/pub/data/isis/topside_sounder/ionogram_cdf/isis2/ACN_08S_346E/> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/b96bf16a-3959-46be-a32c-2e4706129dd1> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.584780"^^xsd:dateTime ;
    dcat:accessURL <ftps://spdf.gsfc.nasa.gov/pub/data/isis/topside_sounder/ionogram_cdf/isis2/ACN_08S_346E/> ;
    dcat:mediaType "application/octet-stream" .

<https://data.nasa.gov/dataset/a3dee6b1-bd4b-4589-b5ad-dba08cd4c3a0/resource/cfd1abf3-daac-4ed0-8dc2-890ba94016cb> a dcat:Distribution ;
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    dct:modified "2026-08-10T19:03:09.585694"^^xsd:dateTime ;
    dcat:accessURL <https://spdf.gsfc.nasa.gov/isis/isis-status.html> ;
    dcat:mediaType "text/html" .

<https://data.nasa.gov/organization/dbb294e4-8597-44f5-aaf4-c0baac12cdbc> a org:Organization ;
    skos:prefLabel "NASA" ;
    foaf:name "NASA" .