This bundle contains open-loop radio receiver data collected at the
Goldstone (California, USA) 64-m antenna of the NASA Deep Space Network
(DSS-14) during the Voyager 2 encounter with Jupiter on day 1979-191.
The data include samples from receiver outputs at S-band (13 cm
wavelength) and X-band (3.6 cm) in right-circular polarization.  Also
included are calibration measurements collected within a few hours of
the Jupiter observations.  The data supported investigations of the
structure of Jupiter's neutral atmosphere and ionosphere among other
objectives.

41 original data tapes -- known as Original Data Records (ODRs) --
were delivered to the Voyager Radio Science Team in the Reconstructed
Data Record (REDR) format.  Each original tape forms the basis for a
PDS4 product in the bundle.  The binary file is the first part of the
product; but the binary data are in an archaic binary format, so they
have been converted to ASCII for easier reading.  There is one ASCII
table with record header/trailer data and two ASCII files with the
receiver samples -- one with S-band samples and the other with X-band
samples.  These are the second, third, and fourth parts of each PDS4
product.  Future users of these data are likely to prefer working
with the ASCII files.  Each product also includes a detached PDS4
label file wrtten in XML and a small ASCII file with field titles for
the header/trailer table.  For example, the following six files
constitute one PDS4 product:

  vp095x.odr                       original ODR file (binary)
  vg2j_14mr_1979191t131727.hdr     header/trailer data (ASCII)
  vg2j_14sr_1979191t131727.tab     S-band receiver samples (ASCII)
  vg2j_14xr_1979191t131727.tab     X-band receiver samples (ASCII)
  vg2j_14mr_1979191t131727.xml     PDS4 XML label (ASCII)
  vg2j_14mr_1979191t131727.txt     field headers for hdr file (ASCII)

In a small number of cases, records could not be read from the ODR
tape that was delivered to the Voyager Radio Science Team.  A
replacement record has been substituted.  In these cases, Field 6
in the binary replacement record (Field 3 in the ASCII header/trailer
record) has been set to '2', and the corresponding receiver output
samples have been set to '0'.

Each ODR has been processed to give a 'browse' product with a
histogram of data sample values, a plot of average sample power versus
time, and a plot of time-averaged power spectra.  There are 41 browse
products; each includes a pair of plots in PDF/A-1b format -- one for
S-band and one for X-band.

The browse collection also includes two products with partially
processed data -- one from the ingress occultation and one from the
egress occultation.  Each is a separate PDS4 ASCII table.  These
tables were recovered from holdings of the NASA Space Science Data
Coordinated Archive (NSSDCA).  No other data from the Voyager 2
Jupiter radio occultation have been archived previously with either
NSSDCA or PDS.

Also included in the bundle are reconstructions of the spacecraft
trajectory and spacecraft high-gain antenna pointing, which was
offset during the Jupiter atmospheric occultation to compensate for
refraction.  Receiver tuning data, included in the ODR header/trailer,
and estimated frequency of the spacecraft ultrastable oscillator
(USO) allows calculation of the exact received frequency at the
ground station.

The document collection includes a description of the Voyager mission,
a Software Interface Specification (SIS) for the archive bundle, and
a description of the high-gain antenna pointing reconstruction
procedure.  The SIS (sis_vgj_rs) describes in more detail how the
products in this archive were constructed from the original raw data
files.  Documentation of the binary formats in the ODR, which
has been archived elsewhere in PDS, has been included by reference.
The SIS provides more description of the archive than can be included
here.

Dick Simpson
2023-12-20