Data Set Overview
    =================
      The UltraViolet Spectrometer (UVS) on the Galileo spacecraft took
      unique data of Comet Shoemaker-Levy/9's impact with Jupiter.  A
      preliminary analysis of this data is presented in this submission to
      the Planetary Data System (PDS).  It consists of two small tables
      with detached labels and documentation.
 
 
    Background
    ==========
      Galileo observed the S-L9 fragment G impact by oscillating the
      scan-platform so that the fields of view of the scan-platform
      instruments moved to-and-fro across Jupiter. Each to-and-fro 'swath'
      lasted 10 2/3 sec, and consisted of two 5 1/3 sec 'passes'.
 
      During the observations, the UVS acquired one measurement every 7.6
      msec (more precisely, 4.0/528 sec); during each measurement, the
      counting gate was open for 6.0 msec. Thus, each 10 2/3 sec swath
      contained 1408 6-msec samples. The data-taking was, however, not
      continuous, and the data received was occasionally corrupted.  The
      data presented here and used in Hord et al. (1995) [HORDETAL1995]
      has all been inspected and verified.
 
 
    Tables in the Dataset
    =====================
      The following is a list of the UVS data files for the Shoemaker-Levy
      fragment R and G impacts. Each file record represents one UVS RIM of
      fourteen spectra, with a duration of 60.666 seconds.
 
 
  FILENAME               FIRST RECORD STARTS AT     LAST RECORD STARTS AT
                         SCLK                       SCLK AT SPACECRAFT
                         UTC                        UTC  AT SPACECRAFT
  ------------------------------------------------------------------------
  Experimenter Data Records (EDRs)
 
  GFRAGTIM.DAT           2486477:00                 2486487:00
                         1994-199//07:02:14.445     1994-199//07:12:21.112
 
  RFRAGTIM.DAT           2490632:00                 2490643:00
                         1994-202//05:03:24.284     1994-202//05:14:31.617
 
 
      Details of the structure and contents of these tables may be found
      in the discussion below as well as in the detached PDS label.
 
      GFRAGTIM.DAT
      ------------
      This file contains the G fragment data and a timescale. Each record
      has a 10 point header and 8008 data points.
 
      Record 0 is the time scale. Each position holds the number of
      seconds from the start of the rim for the corresponding position in
      a data record. The header values of this record are zeros.
 
      Records 1 to 11 contain all data records. The data starts at
      position 10. All fiducials (except the 1st one in each Rim) have
      been replaced with 44 -1's and there are an additional 84 -1's at
      the end of each record to represent the 84 missing bytes in the last
      spectra.
 
      Header info for data records:
 
         0 = rim timetag (Spacecraft Event Time)
       1-5 contain the SCET converted to UTC format; value is at the s/c
         1 = year
         2 = day of year
         3 = hours
         4 = minutes
         5 = seconds
         6 = time value in seconds used to convert from SCET to earth based
             observation time.
 
      NOTE: There is a single -1 in record 6.  This is a noise point
      changed by hand. Its previous value was 33.  Also, there is data for
      the end of rim 2486485, but JPL made an error when they made the
      file containing it so it is not included in this file.   There are 2
      fiducials 3 minor frames apart. It looks like a piece of data was
      written at an incorrect time position, over the top of data already
      there.
 
      RFRAGTIM.DAT
      ------------
      This file contains the R fragment data and a timescale.  Each record
      has a 10 point header and 8008 data points.
 
      Record 0 is the time scale. Each position holds the number of
      seconds from the start of the rim for the corresponding position in
      a data record. The header values of this record are zeros.
 
      Records 1 to 9 contain all data records. The data starts at position
      10. All fiducials have been replaced with 44 -1's and there are an
      additional 84 -1's at the end of each record to represent the 84
      missing bytes in the last spectra.
 
      Header info for data records:
 
         0 = rim timetag (Spacecraft Event Time)
       1-5 contain the SCET converted to UTC format
         1 = year
         2 = day of year
         3 = hours
         4 = minutes
         5 = seconds
 
      NOTE: Record 4 is timetagged 2490635:00 and record 5 is 2490639:00.
      This three rim gap is the result of a change in the playback
      requested by NIMS.   At this time, there is no data for record 8
      (2490642).
 
 
    Processing
    ==========
      These files were produced by the Galileo UVS/EUV team at the
      Laboratory for Atmospheric and Space Physics at the University of
      Colorado at Boulder.  The data contained in the files were generated
      during the analysis of UVS data from the Shoemaker-Levy 9 comet
      Fragment G Jupiter impact.  This analysis is reported in Geophysical
      Research Letters, Vol 22, No. 12, pages 1565-1568, June 15, 1995, by
      C.W. Hord, et al. [HORDETAL1995]
 
 
    Software
    ========
      The two tables in this dataset are small and in binary (XDR)
      format.
 
 
    Media/Format
    ============
      This dataset is an electronic submission to PDS but may be included
      on a future CD-ROM volume of UVS data from the Jupiter Tour. Formats
      are based on standards for table objects established by PDS.

Confidence Level Overview
    =========================
      A one second error associated with a missing leapsecond in early
      versions of this data set has been corrected here.