Data Products of the IMP-8 GME:

Full-Telemetry-Resolution (FTR) Data


1. Data Content and Usage (FTR Data)

This data product contains the full science content of the IMP-8 GME measurement set from launch to present. See the instrument description and data descriptions below for additional information.


2. Digital Data Access (FTR Data)


File organization and naming: Each binary file ("type" CNTS or "type" PHAS, abbreviated as "C" and "P" in the binary file names) covers a 4-day span of data. The files are additionally "g-zipped" to compress the data volume. File naming at this time combines the "type" specification with an "interval" number, where interval 101 starts on October 28 1973 and intervals increment sequentially to the present. The concept of intervals originated in the IMP-6 orbit and GME processing strategy. The concept of 4-day intervals was carried over to IMP-8 in the original implementation of the processing system. A table of interval <-> date conversions exists. So e.g. the file C1895.gz in fact includes "CNTS" data from 21-24 June 1993 inclusive.

File Formats:

Users should be aware these data are in a complex and encoded form that will be difficult to use without acquiring and mastering the software and detailed instrument behavior.


3. Analysis Software and Documentation (UNDER CONSTRUCTION):

The source code of all programs are written in Sun FORTRAN and/or C languages. These programs now operate under a Sun 4.1.4 operating system. A makefile which generates the object files and executable programs, is provided. A user's guide for each program provides the general description and input parameters needed. A shell program executes the program. Each program file contains the source codes of each routine, user's guide, makefile, IMP-8 catalog file, and I/O system "FTIO" package object file.


Program and Link to User's Guide


Link to Source Code

(Source codes are stored "G-zip'd" TAR files - please save as "source")

Pulse-Height Matrix Displays


High-Gain Plot:

Display of IMP8 GME LED and MED pulse-height data in matrix format for select 4-day intervals and special (pre-processed) times, plus distribution histograms used in setting MED gain shift factors






Display of IMP8 GME LED and MED pulse-height data in matrix format (any time span), plus "track-centered" histograms



Processed Parameters

(Rates and Fluxes)



Access to all IMP-8 GME rates (LED, MED and VLET, including sectored rates and every readout mode)



Flux/Flex Plot:

Output of IMP-8 GME LED and MED fluxes from "intermediate flux/flex" format files of bin counts and normalizations.

Flux database uses narrower box definitions (most appropriate to galactic cosmic ray and quiet time studies) than the Flex database (which is most appropriate to interplanetary and solar energetic particle studies).




Sectored data (including fields with optional additional file inputs) and fitted anisotropies


File Output

(PC formats)



Output of pulse-height data in the PC-PHA binary format




Output of rate and flux data (from "intermediate" flux or flex files) into the PC-Rate binary format




Intermediate Flux and Intermediate Flex:

Generate files in the flux or flex format for input to FLUXPLOT, FLEXPLOT and PC-RATE




Data Base Time:

Time consistency and file quality check utility program




Overall Documentation, Processing Overview and Status (PARTIALLY COMPLETE ONLY)

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Return to the GME Data page (and access to additional data products)

Return to IMP-8 GME Home page

Questions or Comments

Contact Information

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

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

Authors/Authorizing NASA Official and Curator

Dr. Robert McGuire (see above)
Howard A. Leckner,, (301) 286-9270
Space Physics Data Facility
NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA

Last Modified: Wednesday 5/7/97 (REM)