File: P11GTTHR_FMT.txt                      Version: NSSDC 02/27/2009 
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Hourly Average Interplanetary Cosmic Ray Data from the Pioneer 11 
Geiger Tube Telescope (GTT) Experiment


Date Set Data Coverage: 1973-04-06 to 1991-06-06

Data Set Contact: Dr. John F. Cooper, NASA GSFC SPDF

Experiment: Pioneer 11 Geiger Tube Telescope (GTT) Experiment

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


Dataset Description:

The Pioneer 11 Geiger-Mueller Tube (GTT) experiment measures cosmic ray 
and magnetospheric energetic electron and proton intensities in the energy 
range of 0.06 to 102 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 73-019A-11E 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 annual files 
p11gt_hrYYYY.asc as described below.

This version of the hourly resolution data set was created in 2008 from
a predecessor version to better support the FTPBrowser interface at
https://omniweb.gsfc.nasa.gov/ftpbrowser/p11_part_gtt_1h.html.  It differs from 
its predecessor in the following respects:
(a) the new data set has annual files while the predecessor had 6-month files
(b) the fill value was changed from -1.00E+31 to 1.00E+031
(c) there is a record for every hour in the new data set, even if there are no
GTT data.
The 6-month files of the predecessor hourly data set are at
https://spdf.gsfc.nasa.gov/pub/data/pioneer/pioneer11/particle
/gtt/ip_1hour_ascii/old/

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 (PROTONS 0.61-3.41 MEV)
   RATA- A CHANNEL COUNTING RATE (ELECTRONS > 0.04 MEV, PROTONS > 0.61 MEV)
   RATB- B CHANNEL COUNTING RATE (ELECTRONS > 0.56 MEV, PROTONS > 9. 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))


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/

See also

https://spdf.gsfc.nasa.gov/pub/data/pioneer/pioneer11/particle/
gtt/ip_15min_vmsbin/p11gtt15m.sfdu

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.