Data Set Overview
    =================
      This archive contains a collection of images acquired by the visible
      wavelength charged couple device (VISCCD) channel of the Miniature
      Integrated Camera Spectrometer (MICAS) housed on the Deep Space 1
      (DS1) spacecraft. Specifically, select EDR images of the September
      2001 approach and encounter of comet 19P/Borrelly are provided.
 
      Each image is provided in FITS (Flexible Image Transport System)
      format. A detached and associated PDS (Planetary Data System) ASCII
      label is also provided for each image. Supplemental ancillary files
      and documentation are included.  Additional information regarding the
      FITS format is available at fits.gsfc.nasa.gov.
 
      Parameters [or] [File Naming Scheme]
      ----------       ------------------
      Image product file names within this archive primarily follow the
      form of original names as provided by the DS1 Mission. These naming
      schemes have technical and engineering context and likely have most
      relevance within the DS1-MICAS community. Directory and file names
      are presented in the following form;
 
        The 'data' directory consists of sub-directories;
 
        'near_ccd' and farNN where NN = '01' through '11'
 
        'far01' consists of data acquired earliest during 19P/Borrelly
        approach and 'far11' consists of approach data acquired later yet
        prior to closest approach. The 'near_ccd' directory consists of
        images acquired near or during closest approach.
 
        Filenames within the farNN directories follow the form;
 
          farNN_short_N_N.XXX
 
          where          NN = '01' through '11' as described above
                        N_N = chronological numbering '1_1' through '2_8'
                              (may not be fully inclusive)
 
          and extension XXX = 'fit' for FITS images
                        XXX = 'lbl' for PDS detached ASCII labels
 
                    'short' refers to short observations of Borrelly (SOBs)
                            images principally used for optical navigation
                            and to help establish integration times for
                            MICAS encounter observations.
 
        Filenames within the 'ccd_near' directory follow the form;
 
        NAME.XXX
 
        where        NAME = Mission name variations as described more
                            fully below
 
        And extension XXX = 'fit' for FITS images
                      XXX = 'lbl' for PDS detached ASCII labels
 
 
        The following attempts an explanation of terms, acronyms, or
        characters within the NAME portion of filenames referenced above;
 
        'ccd'    - Charged Couple Device
 
        'rsen'   -  RSEN = Reduced State Encounter Navigation. Part of on-
        'srsen'           board system that processed images to identify,
                          track, and predict location of target object
                          nucleus for spacecraft pointing.
 
        'snip'   - Extracted sections of full-frame images used for
                   autonomous navigation. When the autotracking system
                   identified the target body nucleus, a section of the
                   CCD image (containing nucleus) was extracted and
                   saved onboard as a snip.
 
        'far'    - Indicates phase of Borrelly encounter distances
        'mid'      relative to closest approach.
        'near'
 
        'm1'     - Mosaic images acquired away from predicted location of
        'm2'       target body nucleus. Images acquired for possible
                   later use in the event RSEN would need to recover
                   target body nucleus for tracking purposes.
 
        'bore'   - Bore sighted images acquired between 'm1' and 'm2'
                   images.
 
        'streak' - A successful maneuver was designed where the Borrelly
                   nucleus was allowed to streak across the IR channel
                   slit. CCD streak images were also acquired during this
                   maneuver.
 
        various numbering sequences such as '22_11_36' in filename
        'snip22_11_36'
 
                 - Chronological or sequential indicators for special
                   purpose operation or maneuver, integration time, RSEN
                   usage, etc..
 
 
      Processing
      ----------
      MICAS images originated in raw form (with Mission attached ASCII
      label) as provided by DS1 Mission operations. The original MICAS
      images were re-processed for archive purposed by the University of
      Maryland PDS Small Bodies Node. Processing resulted in; 1) Conversion
      of raw image data into FITS format (original 16-bit image values are
      precisely preserved) and 2) conversion of Mission label into PDS
      compliant detached PDS ASCII label.
 
      Media/Format
      ------------
      This DS1 MICAS 19P/Borrelly archive is presented via on-line internet
      services.

At review these data were determined to be insufficiently documented
      for proper archiving.  The mission and instrument teams failed to
      provide any additional documentation or explanation.  The data are
      preserved in a 'save-the-bits' state with all information that
      could be obtained at the time.  Users are strongly cautioned.