Relations among Pioneer 10 Geiger Tube Telescope
(GTT) data sets at nssdcftp

U. Iowa (J. Van Allen, B. Randall) started providing to NSSDC
hourly- and daily-averaged Pioneer 10 and 11 GTT data in 
vmsbinary format on magnetic tapes in the middle 1980's.  In 
the early 1990's, as part of an archiving effort coordinated 
by the Pioneer Project Office and NSSDC, U.Iowa started 
providing 15-min data to NSSDC, also in vmsbinary.  All these 
data sets had essentially the same words in their data records,
including particle count rates for 12 single-sensor and multi-
sensor (in coincidence) modes.

The aavoldesc.sfd file presents an extensive discussion of all
the spacecraft and instrument characteristics relevant to the 
processing and future usage of the data, as well as the formats
of the binary data records and a bibliography of papers that 
used the GTT data through the early 1990's.

John Cooper, then with NSSDC, created an hourly-averaged ASCII 
data set from 5 single-sensor rates of the 12 count rates 
contained in the 15min binary data set provided by U. Iowa.  
This data set is accessible both via ftp from this directory 
and, with subset and display functionality, from 
http://ftpbrowser.gsfc.nasa.gov/p10_part_gtt_1h.html.

More recently, the 15-min and 1-day PI-provided vmsbinary data 
sets have been converted to ASCII, and they are accessible 
through this directory.

Finally, as part of its permanent archiving effort, NSSDC has 
passed the PI-provided hourly-averaged binary data set through
its "DIOnAS" system to produce the TAR files of binary data.
It is these that are in the one_hour_cruise_phase subdirectory.