Interplanetary Monitoring Platform (IMP-8) Goddard Medium Energy (GME) Experiment Data

IMP-8 (IMP-J) was launched by NASA on October 26, 1973 to measure the
magnetic fields, plasmas, and energetic charged particles (e.g.,
cosmic rays) of the Earth's magnetotail and magnetosheath and of the
near-Earth solar wind. IMP-8 continues to operate.

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.

Some data are available through NSSDC CDAWeb and at the GMER site at
the SPDF. Data at SPDF include:
- Selected instrument rates at 1 hour resolution on (pre-generated
ONLY) 10-day GIF plots
- Selected instrument rates at 1 hour resolution. In 90-day files with
1 file for each rate (typical length 0.1 MByte)
- H and He Fluxes, plus Electrons and Rates at 30 minute resolution
- H, He and Ion Fluxes, plus Electrons and Rates at 6-hour resolution
- Full telemetry resolution data

Data at NSSDC CDAWeb consists of:
- Hourly Averaged High Energy Protons (20- 40 MeV) Data
- PHAS Data: Pulse Height Data from the LED & MED
- MATR Data: Pulse Height Analysis Summary
- Hourly-Averaged High Energy Protons 40-80 MeV Data
- CNTS Data: Count Rates from the VLET, LED, & MED Detectors