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    • THEMIS Ground-based All Sky Imager Keogram, Level-1

    Metadata Updated: March 13, 2026

    THEMIS Ground All Sky Imager Keograms for all observatories. Keograms are composed of thin images slices taken down the middle of all-sky images and graphed against time. Keograms allow for substorm analysis without the need for full sized raw images. The ASI stations each monitor a 170 degree field of view imaging the auroral oval at kilometer resolution. The ASI is comprised of a fisheye lens and CCD in a stainless steel enclosure topped with a transparent acrylic dome. Exposure control ranges from 5 s to 1 ms although the typical data rate is one image every 3 seconds. Silicone heaters keep the instrument within the nominal temperature range. During daylight hours a sun shades deploy to protect the CCD.

    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 August 21, 2025
    Metadata Updated Date March 13, 2026

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date August 21, 2025
    Metadata Updated Date March 13, 2026
    Publisher NASA Space Physics Data Facility (SPDF) Coordinated Data Analysis Web (CDAWeb) Data Services;THEMIS Data Repository at Berkeley
    Maintainer
    Identifier https://doi.org/10.48322/a2pk-b377
    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 70b096f3-e0a6-4a98-a32b-55ebaa4a035a
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.48322/a2pk-b377
    License https://www.usa.gov/government-works
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 8cbced1f0e865252e712ebeca6f1afc0f2f144347d7f74c142b96acc2310c57e
    Source Schema Version 1.1

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