Welcome to the Home Page of the IMP-8

Goddard Medium Energy (GME)

Experiment


Energetic particle data from the IMP-8 Goddard Medium Energy (GME) Experiment provide a comprehensive basis for modulation and acceleration studies at 1 AU and a critical and unique baseline at 1 AU for ongoing studies of cosmic ray modulation and propagation in the outer heliosphere for Pioneer and Voyager investigations. These include work at New Mexico State University, the University of New Hampshire, the University of Maryland, the University of Iowa, Nagoya University, the University of Tasmania and NASA/Goddard Space Flight Center.

The GME instrument has provided continuous observations extending over almost a complete heliospheric cycle from launch in October 1973 and continues to operate with few problems. When combined with the data from essentially identical Goddard experiments on IMP 6 and 7, these cosmic ray and energetic interplanetary particle observations span a period of 26 years. Data from the GME instrument span an energy range of 0.5-450 MeV Hydrogen, 2-450 MeV/nuc Helium, ions from Carbon through the Iron group from several to >100 MeV/nuc and relativistic electrons. The quality of the IMP 8 GME data in terms of particle and energy resolution, and sensitivity, for galactic cosmic ray Hydrogen (2-230 MeV) and Helium (2-450 MeV/nuc) remains comparable to that of any other cosmic ray experiment flown since 1971.

Contents of this page include:

  1. Access to Data (Graphical and Digital)
  2. About the IMP-8 GME Experiment and Team
  3. Other Sites of Interest
  4. Contact Information


I. Access to Data

DATA (GRAPHICAL)
  • Selected instrument rates
    • 5 rates @ 1 hour resolution on (pre-generated ONLY) 10-day GIF plots
    • Data from Oct 1973 to "present" (typically 1-2 month delay to post)
    • Understanding this data
  • H and He SEP Fluxes, plus Electrons and Rates
    • CDAWeb service
    • 71 bands (differential fluxes and rates total) @ 30 minute resolution
      • 30 H differential fluxes 0.5-500 MeV
      • 21 He differential fluxes 1.2-80 MeV/nuc
      • Relativistic electrons 3-18 MeV
      • 18 instrument rates
    • Pulse-height box definitions optimized for Solar Energetic Particle (SEP) studies
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
    • Selectable bands to be plotted, selectable plot time scales (via CDAWeb system)
    • Understanding this data
  • H, He, and Ion SEP Fluxes, plus Electrons and Rates [UNDER CONSTRUCTION]
    • CDAWeb Service
    • 96 bins (differential fluxes and rates, total) @ 6 hour resolution
      • 30 H differential fluxes 0.5-500 MeV
      • 29 He differential fluxes 1.2-500 MeV/nuc
      • 17 Ion differential Fluxes 1.5-40 MeV/nuc in various bands
      • Relativistic electrons 3-18 MeV
      • 18 instrument rates
    • Pulse-height box definitions optimized for Solar Energetic Particle (SEP) studies
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
    • Selectable bins to be plotted, selectable plot time scales (via CDAWeb system)
    • Understanding this data
  • H and He Quiet Time Fluxes [UNDER CONSTRUCTION]
    • CDAWeb Services
    • 26 bands (differential fluxes) @ daily resolution
      • 12 H differential fluxes 24.25 -485 MeV
      • 14 He differential fluxes 24.16-455.5 MeV/nuc
    • Pulse-height box definitions optimized for Quiet Time modulation and galactic cosmic ray studies
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
    • Selectable bands to be plotted, selectable plot time scales (via CDAWeb system)
    • Understanding this data

DATA (DIGITAL)

 

[N.B. Current GME data holdings at NSSDC are now mostly out-of-date. These holdings are in-progress of ingest with the new data sets here. Links to NSSDC will be activated as NSSDC becomes a preferred or alternate source.]

  • Selected instrument rates (ASCII)
    • 5 rates, 1 hour resolution
    • In 90-day files with 1 file for each rate (typical length 0.1 MByte)
    • Data from Oct 1973 to "present" (typically 1-2 month delay to post
  • H and He Fluxes, plus Electrons and Rates (BINARY - SIMPLE STRUCTURE)
    • 71 bins (differential fluxes and rates total), 30 minute resolution
      • 30 H differential fluxes 0.5-500 MeV
      • 21 He differential fluxes 1.2-80 MeV/nuc
      • Relativistic electrons 3-18 MeV
      • 18 instrument rates
    • Pulse-height box definitions optimized for Solar Energetic Particle (SEP) studies
    • In 6-month combined files (typical length 5 MBytes/file)
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
  • H, He and Ion Fluxes, plus Electrons and Rates (BINARY - SIMPLE STRUCTURE)
    • 96 bins (differential fluxes and rates total), 6 hour resolution
      • 30 H differential fluxes 0.5-500 MeV
      • 29 He differential fluxes 1.2-80 MeV/nuc
      • 17 Ion differential fluxes 1.5-40 MeV/nuc
      • Relativistic electrons 3-18 MeV
      • 18 instrument rates
    • Pulse-height box definitions optimized for Solar Energetic Particle (SEP) studies
    • In 2-year combined files (typical length 2 MBytes/file)
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
  • H, He and Ion Fluxes, plus Electrons and Rates (CDF) [UNDER CONSTRUCTION]
    • CDAWeb Services
    • ISTP/IACG CDFs and ASCII
    • Same 96 bins and 6 hour resolution as above
    • Access via the CDAWeb system
  • H and He Quiet Time Fluxes (BINARY - SIMPLE STRUCTURE) [UNDER CONSTRUCTION]
    • 26 bins (differential fluxes), daily resolution
      • 12 H differential fluxes 24.25-485 MeV
      • 14 He differential fluxes 24.16-455.5 MeV/nuc
    • Pulse-height box definitions optimized for "quiet time" modulation and galactic cosmic ray studies
    • In 2-year combined files (typical length 0.16 MBytes/file)
    • Data from Oct 1973 to "present" (typically 3-6 month delay to post)
  • H and He Quiet Time Fluxes (CDF) [UNDER CONSTRUCTION]
    • CDAWeb Services
    • ISTP/IACG CDFs and ASCII
    • Same 26 bins and daily resolution as above
    • Access via the CDAWeb system
  • Full Telemetry Resolution Data (BINARY - COMPLEX STRUCTURE)
    • Full GME data set and data content for life of the mission
    • Highly encoded in a format "close to" telemetry
    • Data format descriptions and available s/w (Sun O/S based)


II. About the IMP-8 GME Experiment and Team


III. Other Sites of Interest


IV. Contact Information

Questions about GME data and/or instrumentation should be directed to the NASA Principal Investigator:

 
Dr. Robert E. McGuire (at Robert.E.McGuire@nasa.gov)
Head, Space Physics Data Facility
Code 672
NASA/Goddard Space Flight Center
Greenbelt MD 20771 USA
 
Phone (with phonemail): 301-286-7794
FAX: 301-286-1771


Author and Curator

Dr. Robert E. McGuire (see above)


Last Modified: 09/23/11 TJK