PDS_VERSION_ID        = PDS3
RECORD_TYPE           = STREAM
OBJECT                = TEXT
  PUBLICATION_DATE    = 2000-03-17
  NOTE                = "Anomalies and discrepancies in the CD Volume set"
END_OBJECT            = TEXT
END

   COMMENTS ON THE STARDUST NAVIGATION CAMERA PREFLIGHT CALIBRATION DATA

  This document contains comments concerning the unusable images found in
  the Stardust Navcam Preflight Calibration Archive.  All unusable images,
  75 in total, have been placed in the /ERRATA directory on this CD and
  should not be used to generate derived products.  These problems can be
  grouped into three distinct categories:

    1) Images that were deemed "unusable" by the scientists conducting
       the calibration.  This situation often arose during the calibration
       process when difficulty arose during the operation of the Ground
       Support Equipment (GSE).

    2) Images have been scanned for required features in the datastream
       and those features were not present.  These features are:

         a) sync pattern of the form 0x0000, at the beginning of each line.

         b) a line count on each line, represented as a 2-byte unsigned
            integer, indicating the current line number.  This counter
            starts at 0 and counts to 1023.  This value should be present
            just after the sync pattern mentioned in part (a) above.

       These two features are generated by the camera as the data was sent
       to the Ground Support Equipment (GSE).  If these features are not
       present in an image, this means that the image was not transferred
       properly and can not be considered a valid image.

    3) Images were found amongst the calibration data, but no record
       was found regarding the circumstances around which the images were
       acquired.  These images, in all likelyhood, are perfectly valid images,
       but information surrounding the acquisition of these images is not
       know.  Required information includes exposure time, filter used,
       radiance value of the calibration source, etc. and can not be
       determined.