PDS_VERSION_ID                = PDS3
RECORD_TYPE                   = STREAM
OBJECT                        = TEXT
  NOTE                        = "Comments on the NEAR SPICE Archive"
  PUBLICATION_DATE            = 2012-12-27
END_OBJECT                    = TEXT
END


COMMENTS ON THE NEAR SPICE DATA ARCHIVE
=======================================

   This document contains comments and errata concerning the NEAR SPICE
   Data Archive.


1. Text Kernel File Format
--------------------------

   All SPICE text kernel files (LSK, PCK, SCLK, IK, FK) provided in
   this data set have lines terminated by only <LF> (UNIX convention.)
   This is dictated by NAIF's archiving approach to include a
   consistent set of UNIX binary (IEEE architecture) and text (<LF>
   only for end of line marker) kernels in the archived data sets.

   However, the format of the text kernels is specified in their
   associated labels as ASCII (INTERCHANGE_FORMAT = ASCII.) This is a
   violation of the PDS standard stating that lines in ASCII files must
   be delimited by the combination of <CR><LF>. This line termination
   treatment is standard practice for SPICE data sets in the PDS.


2. Use of SPACECRAFT_NAME in the Labels
---------------------------------------

   PDS labels for SPICE kernels provided in this data set contain the
   deprecated keyword SPACECRAFT_NAME instead of the keyword
   INSTRUMENT_HOST_NAME. This is standard practice for SPICE data sets in
   the PDS and is dictated by NAIF's archiving approach to make SPICE
   archives for more recent missions consistent with SPICE archives for
   older missions, for which use of SPACECRAFT_NAME was legitimate.


3. Values of INSTRUMENT_NAME in the Labels
------------------------------------------

   PDS labels for SPICE kernels provided in this data do not set the
   keyword INSTRUMENT_NAME to "SPICE KERNELS", that is the name of the
   instrument described by the instrument catalog file SPICE_INST.CAT
   provided in the data set. Instead this keyword is set to either
   "N/A" or the name(s) of the instrument(s) or structure(s), the
   geometric parameters of which a particular kernel file provides.
   While this error does prevent the individual data products from
   being associated with the "SPICE KERNELS" instrument, it does not
   affect usability of the SPICE data provided in this data set in any
   way because the SPICE Toolkit does not use any information from the
   PDS label to access the data.

   The other side of this error is that the data set does not include
   instrument catalog files for the following instruments named in
   the INSTRUMENT_NAME keyword in the PDS labels:

      "MULTI-SPECTRAL IMAGER"
      "NEAR INFRARED SPECTROMETER"
      "NEAR LASER RANGEFINDER"
      "XRAY/GAMMA RAY SPECTROMETER"


4. Missing FILE_RECORDS Keyword in the Binary Kernel Labels
-----------------------------------------------------------

   All labels for binary SPICE kernels provided in this data set are
   missing the FILE_RECORDS keyword, which is required because these
   labels have the RECORD_TYPE keyword set to FIXED_LENGTH. While this
   error violates the PDS standards, it does not affect usability of
   the SPICE data provided in this data set in any way because the
   SPICE toolkit does not use any information from the PDS labels to
   access the data.


5. Non-standard KERNEL_TYPE Value in the Binary PCK Labels
----------------------------------------------------------

   The KERNEL_TYPE keyword in the binary PCK file labels

      erosatt_1998329_2001157_v01.lbl
      erosatt_1999304_2001151.lbl

   is set to "ORIENTATION" which correctly describes the type of data
   provided in the binary PCK files but is not a standard value for
   this keyword.