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The $PDS4_MISSION_NAME Mission Archived SPICE Kernel Data set
Last update: $PRODUCT_CREATION_TIME
Introduction
============
This document describes the $PDS4_MISSION_NAME SPICE kernel data set (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 data set directory structure,
kernels included in the data set, 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.
Back to Table of Contents
Archived 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, FKs,
and MKs -- are UNIX text files, with a line feed character (ASCII 10) at
the end of the line, and binary kernels files -- SPKs, CKs and DSKs --
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:
https://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:
https://naif.jpl.nasa.gov
specifically:
Toolkit: https://naif.jpl.nasa.gov/naif/toolkit.html
Utilities: https://naif.jpl.nasa.gov/naif/utilities.html
Tutorials: https://naif.jpl.nasa.gov/naif/tutorials.html
Lessons: https://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
Marc Costa Sitja
(626) 469-1244
Marc.Costa.Sitja@jpl.nasa.gov
Back to Table of Contents
Cognisant Persons
===============================
This archive was produced by Marc Costa Sitja and Alfredo Escalante
Lopez, ESA SPICE Service, Archives and SPICE Software Development and
Operations Work Area, 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