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    • Alouette-2 Topside Sounder Ionogram Data

    Metadata Updated: March 13, 2026

    These ionograms were digitized from the original Alouette 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/sec. This sample rate is higher than the Nyquist frequency of 30 kHz. The sample frequency of 40 kHz provides a measurement every 25 microseconds corresponding to an apparent range (c*t/2) interval of 3.75 km. The ionograms consist of swept-frequency operation (there is no fixed-frequency operation as in ISIS-1 and ISIS-2). The time resolution between ionograms is typically 31 seconds.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: See this page for license information.

    Downloads & Resources

    Dates

    Metadata Created Date March 13, 2026
    Metadata Updated Date March 13, 2026

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date March 13, 2026
    Metadata Updated Date March 13, 2026
    Publisher NASA Space Physics Data Facility (SPDF) Data Services
    Maintainer
    Identifier /SDE/SPASE_JSON/|811dc3681e0c304b4bdc903e067eb241
    Data Last Modified 2026-03-09
    Category Heliophysics
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 8614d8f4-52df-45a8-961c-09e079559e74
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    License https://www.usa.gov/government-works
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 44990dda2952c4679d2c76efd065bb52de319cdb2b45a0963eb20a6c536e8160
    Source Schema Version 1.1

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