PDS_VERSION_ID                   = PDS3
LABEL_REVISION_NOTE              = "
             2012-08-30, D. Kazden, updated to meet PDS 3.8 standards;
             2020-02-11, D. Kazden, updated cITATION_DESC;"

    OBJECT                         = DATA_SET
  DATA_SET_ID                    = "PVO-V-OETP-5-BOWSHOCKLOCATION-V1.0"

  OBJECT                         = DATA_SET_INFORMATION
    DATA_SET_NAME                  = "PVO VENUS ELECT TEMP PROBE DERVD
                                      BOW SHOCK LOCATION VER 1.0"
    DATA_SET_COLLECTION_MEMBER_FLG = N
    START_TIME                     = 1978-12-05T15:07:34.817
    STOP_TIME                      = 1992-10-06T20:38:35.000
    DATA_OBJECT_TYPE               = TABLE
    ARCHIVE_STATUS = ARCHIVED 
    DATA_SET_RELEASE_DATE          = 1993-10-01
    PRODUCER_FULL_NAME             = "DR. ROBERT F. THEIS"
    DETAILED_CATALOG_FLAG          = N
    ABSTRACT_DESC                  = "The Bow Shock File. This file gives the
    orbit-by-orbit times and locations of the bow shock crossings, which are
    characterized by distinct changes in Ne. Multiple shock crossing are
    listed if they are sufficiently separated to be resolved accurately.
    (Bow shock crossings will be evident in the High Resolution Ne File when
     they occurred within 30 minutes of periapsis)"
    DATA_SET_TERSE_DESC            = "PVO VENUS ELECT TEMP PROBE DERVD BOW
                                             SHOCK LOCATION VER 1.0"
    CITATION_DESC        = "Theis, R. F., PVO-V-OETP-5-BOWSHOCKLOCATION-V1.0,
                 PVO VENUS ELECT TEMP PROBE DERVD BOW SHOCK LOCATION VER 1.0,
                             NASA Planetary Data System, 1993."
    DATA_SET_DESC                  = "
The Bow Shock File.  This file gives the orbit-by-orbit times and
locations of the bow shock crossings, which are characterized by distinct
changes in Ne.  Multiple shock crossing are listed if they are sufficiently
separated to be resolved accurately. (Bow shock crossings will be evident
in the High Resolution Ne File when they occurred within 30 minutes of
periapsis).

The ionopause and bow shock crossing times and locations are easily
identified in the high resolution Ne measurements (Theis et al., 1980).
These files contain the UT, altitude, latitude, SZA and local time of each
crossing.

The bow shock is a much more discrete feature in the data than the
ionopause.  Multiple shock crossings sometimes occur because the shock
often moves at higher velocities than the satellite. In these cases, only the
outer most shock crossing is recorded, unless the separation between the
crossings is greater than a minute or two.  The occurrence of multiple
shocks in the Bow Shock File provides a record of the orbits in which the
solar wind itself was probably highly variable.  Because of the geometry of
the orbit, most shock crossings were in the range of 45 to 135 deg. SZA.
However, the nose region of the shock was explored between 1985 and
1987 when PVO periapsis was near the equator and was at altitudes
between 2000 and 2300 km.  During these years near solar minimum the
nose of the shock often moved down into that altitude range (Russell et al,
1988).  During the subsolar passages of these years, the orbit
approximately paralleled the shock, sometimes inside, sometimes outside,
thus providing interesting snapshots of its movements."

    CONFIDENCE_LEVEL_NOTE          = "
The bow shock is selected from 200 minute pass plots by marking the UT
of the sharp change in the amplitude of Ne at the shock discontinuity.  The
resolution of the shock crossing time is of the order of 1 minute on these
plots, but this could be improved to a few seconds if expanded plots were
used.  There is no plan currently to provide the ultimate resolution
available in bow shock crossing time and location."

  END_OBJECT                     = DATA_SET_INFORMATION
    OBJECT                           = DATA_SET_MISSION
    MISSION_NAME                   = "PIONEER VENUS"
  END_OBJECT                       = DATA_SET_MISSION

  OBJECT                         = DATA_SET_TARGET
    TARGET_NAME                    = VENUS
  END_OBJECT                     = DATA_SET_TARGET

  OBJECT                         = DATA_SET_HOST
    INSTRUMENT_HOST_ID             = PVO
    INSTRUMENT_ID                  = ONMS
  END_OBJECT                     = DATA_SET_HOST

  OBJECT                         = DATA_SET_REFERENCE_INFORMATION
    REFERENCE_KEY_ID             = "RUSSELLETAL1988"
  END_OBJECT                     = DATA_SET_REFERENCE_INFORMATION

  OBJECT                         = DATA_SET_REFERENCE_INFORMATION
    REFERENCE_KEY_ID             = "THEISETAL1980"
  END_OBJECT                     = DATA_SET_REFERENCE_INFORMATION

END_OBJECT                     = DATA_SET
END