File: P10GTTHR_FMT.txt                      Version: NSSDC 11/15/2001 JFC
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Hourly Average Interplanetary Cosmic Ray Data from the Pioneer 10 
Geiger Tube Telescope (GTT) Experiment


Date Set Data Coverage: 1972-03-03 to 1991-06-30

Data Set Contact: Dr. John F. Cooper, RSTX/SSDOO, NASA GSFC

Experiment: Pioneer 10 Geiger Tube Telescope (GTT) Experiment

Principal Investigator: Prof. James A. Van Allen, University of Iowa


Dataset Description:

The Pioneer 10 Geiger-Mueller Tube (GTT) experiment measures cosmic ray 
and magnetospheric energetic electron and proton intensities in the energy 
range of 0.06 to 10^2 MeV. This data set consists of hourly averages of 
selected interplanetary counting rates computed by NSSDC staff from 15-min. 
averaged data in the full VMS binary data set 72-012A-11D in the NSSDC 
tape archive. Users needing this full data set should apply via e-mail to 
request@nssdca.gsfc.nasa.gov. The hourly data are in the files 
P10GTyyn.asc as described below.

Data Parameters:

   NYY NDOY MHR MMN NSEC NTSAMP RATGG RATA RATB RATC RATD RSCS HLATSC

Data Parameter Definition:

   NYY - YEAR (SCET)
   NDOY- DAY OF YEAR (SCET)
   MHR - HOUR
   MMN - MINUTE
   NSEC - SECONDS
   NTSAMP - DATA SAMPLES NORMALIZED TO 2048 BPS TELEMETRY RATE
   RATGG- G+G COUNTING RATE (ELECTRONS > 0.06 MeV, PROTONS > 25 MEV)
   RATA- A CHANNEL COUNTING RATE (ELECTRONS > 5 MEV, PROTONS > 30 MEV)
   RATB- B CHANNEL COUNTING RATE (ELECTRONS > 0.55 MEV, PROTONS > 6.6 MEV)
   RATC- C CHANNEL COUNTING RATE (ELECTRONS > 21 MEV, PROTONS > 80 MEV)
   RATD- D CHANNEL COUNTING RATE (ELECTRONS > 31 MEV, PROTONS > 80 MEV)
   RSCS- SUN-SPACECRAFT DISTANCE (AU)
   HLATSC- HELIOGRAPHIC LATITUDE OF SPACECRAFT (DEGREES)

FORTRAN Statement for Data File Format:

      WRITE(IPRT,1234) NYY,NDOY,MHR,MMN,NSEC,NTSAMP,RATGG,RATA,RATB,
     *   RATC,RATD,RSCS,HLATSC
1234  FORMAT(1X,I2,1X,I3,3(1X,I2),1X,I5,1X,3F8.3,2F7.3,2(1X,F8.4))

File Structure:

The COHO data files are divided into six-month blocks. For example, 
P10GT73A.asc includes data for Jan.-Jun. of 1973 while P10GT73B.asc
has data for Jul.- Dec. of 1973.

Related Information and Data:

Further details on the spacecraft, experiment, data sets at NSSDC, and related
WWW sites can be found on the Pioneer 10/11 flight project page under

http://nssdc.gsfc.nasa.gov/space/

Hour averages of the interplanetary solar wind data from, and hourly heliocentric
coordinates of, Pioneer 10/11 and other interplanetary spacecraft may be also
be accessed and plotted on-line through the COHOWeb service based at the same
WWW site as above.

Acknowledgement:

Use of these data in publications should be accompanied at minimum by
acknowledgements of the National Space Science Data Center and the responsible
Principal Investigator defined in the experiment documentation provided here.
Citation of NSSDC's Coordinated Heliospheric Observations (COHO) data base
would also be appreciated, so that other potential users will be made aware of
this service.