aareadme file at 
ftp/spacecraft_data/explorer/explorer35/plasma_probe/3-min_interplanetary_plasma_param/old/aareadme_v2.txt
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This directory provides access to 1967 and 1968 files of
3-min plasma parameter data in ASCII format, from the MIT
Faraday Cup flown on Explorer 35.  This ASCII data set was 
created by GSFC's Space Physics Data Facility in 2010 as 
"Version 2" from the "Version 1" data set also contained in 
this directory.  See higher level aareadme for the differences
among Version 1, 2 and 3 data sets.

The format of the ASCII data set is:

Word number        Format      Description

 1          I4        Year (1967,1968)
 2          I4        Day of year(1-366)
 3          I3        Hour of day (0 . 23)
 4          I3        Minute of hour (0 . 59)
 5          I3        Second of minute (0 . 59)
 6          I7        Spacecraft counter value
 7          F6.1      Ion density (number/cc)
 8          I4        aberrated flow speed (km/s)
 9          F6.1      Aberrated flow longitude (deg) (see note)
10          F6.1      Aberrated flow latitude (deg) (see note)
11          I4        Thermal speed (km/s)
12-13       2F6.1     Flow angles, spacecraft
                         coords, not normally used
14          F6.1      True longitude of flow (see note)
15          F6.1      True latitude of flow (see note)
16          I6        True flow speed
17          F6.1      Solar ecliptic longitude of s/c spin axis
18          F6.1      Solar ecliptic latitude of s/c spin axis
19-21	    3F8.3     S/C position X,Y,Z in GSE, Re
22-24	    3F8.3     S/C position X,Y,Z in SSE,   see notes below


Note:  Flow angles give the GSE directions from which the
flow comes.  "Aberrated" directions are as observed.  "True"
directions are with the 30 km/s motion of the Earth (and its
orbiting spacecraft) about the sun removed.

Note: SSE coordinates are Selenocentric Solar Ecliptic, having
its X axis from the moon to the sun and Z axis normal to
the ecliptic plane, positive northward.  Components are 
given in units of lunar radii.

Note: The GSE and SSE position vectors were taken from the 81.92s-
resolution Explorer 35 magnetic field data set accessible from
https://spdf.gsfc.nasa.gov/pub/data/explorer/explorer35/
gsfc_magnetometer/82s_mag_data_ascii/.  The position vectors we
added to the 3-min plasma records had the first 81.92s time stamp 
following the 3m time stamp of the plasma record, as long as the
former was not more than 3 minutes later than the latter.
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