+-----------------------------------------------------------------------------+ | __ __ __ __ __ __ ___ __ ___ __ __ ___ | | /__\ /__` '__\ /__` |__) | / ` |__ /__` |__ |__) \ / | / ` |__ | | \__, .__/ \__/ .__/ | | \__, |___ .__/ |___ | \ \/ | \__, |___ | | | +-----------------------------------------------------------------------------+ The $PDS4_MISSION_NAME Mission Archived SPICE Kernel Dataset Last update: $PRODUCT_CREATION_TIME Introduction ============ This document describes the $PDS4_MISSION_NAME SPICE kernel dataset (SKD) containing observation geometry and other ancillary data in the form of SPICE System kernel files for the $PDS4_SPACECRAFT_NAME spacecraft its instruments and targets. It describes the dataset directory structure, kernels included in the dataset, their naming conventions, and provides pointers to the SPICE software and documentation. Table of Contents ================= Introduction Table of Contents Overview Errata Archive Contents Kernel Types Kernel Details SPK Files PCK Files IK Files CK Files LSK Files SCLK Files FK Files DSK Files MK Files SPICE Software and Documentation Contact Information Overview ======== This archive includes the complete set of $PDS4_MISSION_NAME SPICE data files (kernel files), which can be accessed using SPICE software. The SPICE data contain geometric and other ancillary information needed to recover the full value of science instrument data. In particular SPICE kernels provide spacecraft and planetary ephemerides, spacecraft and instrument orientation, instrument mounting alignments, and data needed for relevant time conversions. Data in the SPICE kernel files must be accessed using the software called the SPICE Toolkit produced and distributed by the Navigation and Ancillary Information Facility (NAIF) Node of the Planetary Data System. This archive includes data covering from $PDS4_MISSION_NAME launch, through the end time of the latest spacecraft orientation file supplied in the archive. Until the end of the spacecraft lifespan this archive will be accumulating with new data added according to the project archiving plan. Back to Table of Contents Errata ====== $ERRATA Back to Table of Contents Archive Contents ================ Files in this archive are organized into a set of subdirectories below the top-level directory. The following diagram shows the structure and content of these directories. The directory names are enclosed in square brackets ([]). [top-level-directory] | |- bundle_$MISSION_ACCRONYM_spice_v*.xml Bundle PDS4 label, one or more versions. |- readme.txt Bundle top-level readme file. | |-[spice_kernels] Directory containing SPICE kernels. | | | |- collection_spice_kernels_v*.xml PDS4 labels for Spice Kernels collections. | |- collection_spice_kernels_inventory_v*.tab | | Spice Kernels collections' inventories. | | | |-[ck] Directory containing CK files. | | | | | |-- *.bc Binary CK files. | | +-- *.xml PDS4 labels for CK files. | | | |-[dsk] Directory containing DSK files. | | | | | |-- *.bds Binary DSK files. | | +-- *.xml PDS4 labels for DSK files. | | | |-[fk] Directory containing FK files. | | | | | |-- *.tf Text FK files. | | +-- *.xml PDS4 labels for FK files. | | | |-[ik] Directory containing IK files. | | | | | |-- *.ti Text IK files. | | +-- *.xml PDS4 labels for IK files. | | | |-[lsk] Directory containing LSK files. | | | | | |-- *.tls Text LSK files. | | +-- *.xml PDS4 labels for LSK files. | | | |--[mk] Directory containing MK files. | | | | | |-- *.tm Text Meta-kernel files. | | +-- *.xml PDS4 labels for MK files. | | | |-[pck] Directory containing PCK files. | | | | | |-- *.tpc Text PCK files. | | |-- *.bpc Binary PCK files. | | +-- *.xml PDS4 labels for PCK files. | | | |-[sclk] Directory containing SCLK files. | | | | | |-- *.tsc Text SCLK files. | | +-- *.xml PDS4 labels for SCLK files. | | | +-[spk] Directory containing SPK files. | | | |-- *.bsp Binary SPK files. | +-- *.xml PDS4 labels for SPK files. | +-[document] Directory containing documents. | |- collection_document_v*.xml PDS4 labels for document collections. |- collection_document_inventory_v*.tab | Document collections' inventories. | |- spiceds_v*.html This file and its earlier versions. +- spiceds_v*.xml PDS4 labels for this file and its earlier versions. Back to Table of Contents Kernel Types ============ Different SPICE kernel types are used to store different kinds of ancillary data. SPK (Spacecraft Planet Kernel) files contain ephemerides (position and velocity) for spacecraft, planets, satellites, comets and asteroids as well as for moving or fixed spacecraft and instrument structures. SPK files are located under the spice_kernels/spk directory of this archive. PCK (Planetary Constants Kernel) files contain certain physical, dynamical and cartographic constants for target bodies, such as size and shape specifications, and orientation of the spin axis and prime meridian. PCK files are located under the spice_kernels/pck directory of this archive. IK (Instrument Kernel) files contain instrument parameters relevant for computing an instrument's geometry such as field-of-view definitions, CCD and optical distortion characteristics, and internal timing parameters. IK files are located under the spice_kernels/ik directory of this archive. CK (C-matrix Kernel) files contain time varying orientations for spacecraft, spacecraft structures, and articulating science instruments. CK files are located under the spice_kernels/ck directory of this archive. LSK (Leapseconds Kernel) files contain the leapseconds and the values of other constants required to perform a transformation between Universal Time Coordinated (UTC) and Ephemeris time (ET), which is also known as Barycentric Dynamical Time (TDB). LSK files are located under the spice_kernels/lsk directory of this archive. SCLK (Spacecraft Clock Kernel) files contain on-board clock calibration data required to perform a transformation between Ephemeris time (ET) and spacecraft on-board time (SCLK). SCLK files are located under the spice_kernels/sclk directory of this archive. FK (Frame definitions Kernel) files contain information required to define reference frames, sources of frame orientation data and connections between these frames and other frames supported within the SPICE system. The science instrument frame definitions provided in the FK files include mounting alignment information for the instruments. FK files are located under the spice_kernels/fk directory of this archive. DSK (Digital Shape Kernel) files contain detailed shape models for extended objects. These objects typically are solar system bodies such as planets, dwarf planets, natural satellites, asteroids, and comet nuclei. DSK data also can represent shapes of artificial objects such as spacecraft components or represent abstractions such as a magnetic field model. DSK files are located under the spice_kernels/dsk directory of this archive. MK (Meta-Kernel) files list sets of related SPICE kernels that should be used together, providing an easy way to make data from these kernel sets available to a SPICE-based application by loading meta-kernels into the program using the high level SPICE data loader routine FURNSH. MK files are located the spice_kernels/mk directory of this archive. Kernel Details ============== The subsections below provide details, such as file naming conventions and specific details, for each of the kernel types included in this archive. Please note that the most detailed description of the data in each file is provided in metadata included inside the file or the comment area of the file. For binary files this information can be viewed using the utility program COMMNT included in the NAIF Toolkit. Back to Table of Contents $SPK_AAREADME Back to Table of Contents $PCK_AAREADME Back to Table of Contents $IK_AAREADME Back to Table of Contents $CK_AAREADME Back to Table of Contents $LSK_AAREADME Back to Table of Contents $SCLK_AAREADME Back to Table of Contents $FK_AAREADME Back to Table of Contents $DSK_AAREADME Back to Table of Contents MK Files Meta-kernel (MK) files (a.k.a 'furnsh' files) provide lists of the archived kernels included in this archive suitable for loading into a SPICE-based application via the high level SPICE data loader routine FURNSH. Using meta-kernels makes it easy to load with one call a comprehensive SPICE data collection for a given period. The text MK files are provided under the spice_kernels/mk directory and are named according to the following scheme: - $PDS4_MISSION_NAME MK files $MISSION_ACCRONYM_vVVV.tm where VVV is the version; the file with the latest version supersedes all similarly named files with earlier versions. The reasons for adding new kernels include (but are not limited to) adding new kinds of kernels, adding new versions of existing kernels containing more complete or more accurate data, and adding new versions of existing kernels superseding the existing kernels that had errors. The file with the latest version number supersedes all earlier versions. Although the meta-kernels were created such that on a UNIX workstation they can be loaded into a SPICE-based application directly from the directory in which they reside -- because the PATH_VALUES keyword is set to '..' and '/' is used as the path delimiter -- it is recommended that users make local copies of these files and update the PATH_VALUES keyword in each of them to point to the actual location of the archive's 'spice_kernels' directory on their system. Additional changes including replacing '/' and '\' in all path specifications and converting UNIX line terminators to terminators native to the user's system may be required to use these meta-kernels on non-UNIX workstation. The following guidelines were followed to pick and set priority -- determined by the order in which the kernel files are listed, with the latest one taking precedence -- for the kernel files included in these meta-kernels: - the latest archived versions of LSK, PCK, SCLK, IK, FK, generic SPKs, fixed offset SPKs, and fixed orientation CKs were included - the latest reconstructed SPKs were included - the latest predicted and reconstructed CKs were included Additional description of the kernels sets listed in a text MK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program. Back to Table of Contents File Formats ============ All text documents and other meta information files such as descriptions, detached PDS4 labels, and inventory tables are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of the records. This allows the files to be read by most operating systems. The text kernel files in this archive -- LSKs, PCKs, SCLKs, IKs, and FKs -- are UNIX text files, with a line feed character (ASCII 10) at the end of the line, and binary kernels files -- SPKs and CKs -- are IEEE LSB binary files. While data files in this archive can be used 'as is' with SPICE toolkits for the majority of supported environments, converting the files to the binary or text format native to the user's computer may be required for use of the data with FORTRAN toolkits on incompatible environments. Refer to the documentation provided with the SPICE Toolkit to find out whether conversion is needed in each specific case. NAIF provides a tool (BINGO) that can convert either binary or text kernels from one format to another. This means that text files can have their line terminator changed and binary files can be converted to the native format of the platform of interest. BINGO is available from the utilities page at the NAIF Node of the PDS: http://naif.jpl.nasa.gov/naif/utilities.html Back to Table of Contents SPICE Software and Documentation ================================ The latest SPICE Toolkit for a variety of computer platforms, additional utility programs, documentation, tutorials, and hands-on lessons are available at the NAIF Node of the PDS: http://naif.jpl.nasa.gov specifically: Toolkit: http://naif.jpl.nasa.gov/naif/toolkit.html Utilities: http://naif.jpl.nasa.gov/naif/utilities.html Tutorials: http://naif.jpl.nasa.gov/naif/tutorials.html Lessons: http://naif.jpl.nasa.gov/naif/lessons.html Back to Table of Contents Contact Information =============================== If you have any questions regarding this directory or its contents, please contact the ESA SPICE Service: $PRODUCER_NAME $PRODUCER_PHONE $PRODUCER_EMAIL or NAIF at JPL: Boris Semenov (818) 354-8136 Boris.Semenov@jpl.nasa.gov Back to Table of Contents Cognisant Persons =============================== This archive was produced by $PRODUCER_NAME, ESA SPICE Service, Cross Mission Support Office (SCI-OPM), Data and Engineering Division (SCI-OP), Directorate of Science (D/SCI), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Villanueva de la Canada, Spain. End of $PDS4_MISSION_NAME SPICE archive description. Back to Table of Contents