PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Comments on the MSL SPICE Archive" PUBLICATION_DATE = 2018-07-31 END_OBJECT = TEXT END COMMENTS ON THE MSL SPICE DATA ARCHIVE ====================================== This document contains comments and errata concerning the MSL 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 (UNIX convention.) This is dictated by NAIF's archiving approach to include a consistent set of UNIX binary (IEEE architecture) and text ( 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 . 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: "ALPHA PARTICLE X-RAY SPECTROMETER" "CHEMISTRY AND MINERALOGY" "CHEMISTRY CAMERA LASER INDUCED BREAKDOWN SPECTROMETER" "CHEMISTRY CAMERA REMOTE MICRO-IMAGER" "COLLECTION AND HANDLING FOR IN-SITU MARTIAN ROCK ANALYSIS" "CRUISE MEDIUM GAIN ANTENNA" "CRUISE STAGE" "DESCENT STAGE LOW GAIN ANTENNA" "DESCENT STAGE UHF ANTENNA" "DUST REMOVAL TOOL" "DYNAMIC ALBEDO OF NEUTRONS" "HAZARD AVOIDANCE CAMERA" "HIGH GAIN ANTENNA" "MARS DESCENT IMAGER" "MARS HAND LENS IMAGER" "MAST CAMERA" "NAVIGATION CAMERA" "PARACHUTE CONE LOW GAIN ANTENNA" "PARACHUTE CONE UHF ANTENNA" "POWDER ACQUISITION DRILL SYSTEM" "RADIATION ASSESSMENT DETECTOR" "REMOTE SENSING MAST" "ROBOTIC ARM" "ROVER ENVIRONMENTAL MONITORING STATION" "ROVER LOW GAIN ANTENNA" "ROVER UHF ANTENNA" "ROVER" "SAMPLE ANALYSIS AT MARS" "TILTED LOW GAIN ANTENNA" 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. START_TIME and STOP_TIME in Rover Path SPK Labels ---------------------------------------------------- The START_TIME and STOP_TIME keywords in the rover path SPK files normally covering a range of SOLs are not set to the bounds of the rover location coverage but to the much wider coverage for the site locations along the rover path, e.g. START_TIME = 2000-12-31T23:58:56 STOP_TIME = 2099-12-31T23:58:53 The coverage SOL range is specified in the file name, the label DESCRIPTION keyword and in the file comments. 6. Data Not Provided in Release 0001 ------------------------------------ The following kernels were not available at the release 0001 time: - reconstructed cruise attitude CK modeling spin during the whole cruise, by the MSL ACS Team - reconstructed cruise attitude CK by the MSL NAV Team - separate IKs for non-camera instruments They will be added to the archive in one the future releases. 7. Incorrect SOL Range in DESCRIPTION ------------------------------------- The DESCRIPTION field in the labels of kernels covering the SOL range 1772 to 1869 (data/*/*1772_1869*.lbl) incorrectly states that the range is SOLs 1648 to 1772. End of errata.