PDS_VERSION_ID                  = PDS3
RECORD_TYPE                     = STREAM
DATA_SET_ID                     = "HST-S-WFPC2-3-RPX-V1.0"

OBJECT                          = TEXT
  PUBLICATION_DATE              = 1998-09-16
  NOTE                          = "Description of the index files
provided on this volume."
END_OBJECT                      = TEXT
END

              DESCRIPTION OF INDEX FILES ON THIS VOLUME
              -----------------------------------------

The INDEX directory contains the indices for the data files found on
this volume.  The files in this directory are:

    INDXINFO.TXT - This file.

    INDEX.TAB    - Data file index.  This file is a table containing
                   one row for each data file found on the volume.
    INDEX.LBL    - PDS label for INDEX.TAB.

    CUMINDEX.TAB - Cumulative data file index.  This file is a
                   concatenation of the INDEX.TAB files on all five
                   volumes of this data set.
    CUMINDEX.LBL - PDS label for CUMINDEX.TAB

    OBSINDEX.TAB - 'Observation' index.  This file is a table
                   containing one row for each distinct image
                   found on the volume.  Note that each individual
                   WFPC2 data file contains four different images,
                   designated PC1, WF2, WF3, and WF4.
    OBSINDEX.LBL - PDS label for OBSINDEX.TAB

    OBSCMIDX.LBL - Cumulative observation index.  This file is a
                   concatenation of the OBSINDEX.TAB files on all five
                   volumes of this data set.
    OBSCMIDX.TAB - Cumulative data set record for all volumes.

USAGE NOTES
-----------

These indices are all provided as ASCII text files, in which columns
are all of fixed width and are separated by commas.  Character strings
are always enclosed by double quotation marks (").  Each record is
terminated by a carriage return/line feed pair.  This format of file
can be read directly into many database management systems.

For each index file (*.TAB), the corresponding label file (*.LBL)
describes the file format, including a detailed description of the
contents of each column.

There is a perhaps somewhat subtle distinction between the data file
index INDEX.TAB and the observation index OBSINDEX.TAB.  The former
contains one record for each DATA FILE found on the volume.  Files of
different types (BROWSE, CALIMAGE, CALMASK, RAWIMAGE, RAWMASK,
ENGDATA, ENGMASK, and HEADER) all appear as separate rows of the
table.  This index also includes a number of WFPC2-specific properties
of the images, such as filter name, gain mode, etc.

The observation index instead contains information on each INDIVIDUAL
CALIBRATED IMAGE found in the file.  This information is not
duplicated for each different file type.  However, each calibrated
WFPC2 data file contains four different images, designated PC1, WF2,
WF3, and WF4, so it appears as four different rows of the table.  This
index includes information that is often unique to each individual
image, such as pointing geometry and calibration factors.  For the
most part, this table does not provide information that is specific to
WFPC2; the columns in this table are general and could be used to
describe any planetary ring image.