The HAYABUSA2 SPICE Data Archive
=======================================================================
Last update: Jan 16, 2017
Introduction
============
This document describes the Hayabusa2 SPICE archive, containing
observation geometry and other ancillary data in the form of SPICE
System kernel files for the Hayabusa2 spacecraft and its instruments
and targets. It describes the archive directory structure, kernels
included in the archive, 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
Archived Kernel Details
SPK Files
PCK Files
IK Files
CK Files
LSK Files
SCLK Files
FK Files
MK Files
File Formats
Reference
Contact
Overview
========
This archive includes a part of Hayabusa2 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
alighments, 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.
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Errata
======
None.
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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]
|
|- readme.txt Bundle top-level readme file.
|
|-[spice_kernels] Directory containing SPICE kernels.
| |
| |-[ck] Directory containing CK files.
| | |
| | |-- *.bc Binary CK files.
| | |-- *.xml PDS4 labels for CK 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.
| | |-- *.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 document collection.
|
|- spiceds_v*.html This file and its earlier versions
|- spiceds_v*.xml PDS4 labels for this file and its earlier versions.
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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 leap seconds 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.
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.
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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.
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SPK Files
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.
This archive includes binary SPK files containing the following
kinds of ephemeris data:
- planetary ephemeris SPKs
These SPKs contain ephemeris data for the Solar System
planet barycenters, and Sun, Mercury, Venus, Earth, and Moon.
They are produced by the JPL Solar System Dynamics group
and are named DEXXX, e.g. DE430.
- final ephemeris of the Hayabusa2 spacecraft
These SPKs contain final ephemeris data for the Hayabuas2
spacecraft based on the precise after-the-fact OD solutions.
This archive includes binary SPK files under the spice_kernels/spk
directory and are named according to the following scheme:
- planetary ephemeris SPKs
deVVVs.bsp
where
VVV is the ephemeris version
s (optional) indicates that the original file
coverage was shortened to reduce the file
size.
- Hayabusa2 final ephemeris
hyb2_YYYYMMDD-yyyymmdd_000II_final_verV.oem.bsp
where
YYYYMMDD is the file coverage start date
yyyymmdd is the file coverage stop date
II is the time interfal
1m ... 1-minute interval
1h ... 1-hour interval
V is the version; the file with the latest
version supersedes all similarly named
files with earlier versions.
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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.
This archive includes generic text PCK files produced by NAIF,
containing data from the reports of the IAU Working Group on
Cartographic Coordinates and Rotational Elements. The generic text
PCK version 00010 contains data from the 2009 report.
The PCK files are provided under the spice_kernels/pck
directory and are named according to the following scheme:
- generic text PCKs
pckVVVVV.tpc
where
VVVVV is the version; the file with the largest
number is the latest, but the user of PCK
data must decide if the latest version,
or an earlier version, is appropriate
for his/her analysis task.
The most detailed description of the data in a text PCK file is
provided in metadata included inside the description area of the
file. This information can be viewed using any text editor program.
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IK (Instrument Kernel) files contain instrument parameters relevant
for computing an instrument's observation geometry such field-of-view
definitions, CCD and optical distortion characteristics, and internal
timing parameters.
This archive includes text IK files for all Hayabusa2 scientific
instruments. These IKs were created by Hayabusa2 instrument teams.
The IK files are provided under the spice_kernels/ik
directory and are named according to the following scheme:
- instrument and antennae IK files
hyb2_NAME_vVV.ti
where
NAME is the instrument acronym
lidar
nirs3
onc
tir
VV is the version; the file with the latest
version supersedes all similarly named files
with earlier versions, but the SPICE user must
decide if the latest version, or an earlier
version, is appropriate for his/her analysis
task.
The most detailed description of the data in a text IK 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
CK Files
CK (C-matrix Kernel) files contain time varying orientations for
spacecraft, articulating spacecraft structures, and articulating
science instruments.
This archive includes binary CK files under th spice_kernels/ck
directory and are named according to the following scheme:
- Hayabusa2 yearly CK files based on House Keeping telemetry
hyb2_hk_YYYY_vVV.bc
where
YYYY is the year covered by the CK kernel
VV is the version; the file with the latest
version supersedes all similarly named files
with earlier versions.
- Hayabusa2 yearly CK files based on AOCSC telemetry
hyb2_aocsc_YYYY_vVV.bc
where
YYYY is the year covered by the CK kernel
VV is the version; the file with the latest
version supersedes all similarly named files
with earlier versions.
The AOCSC telemetry contains larger number of digits than HK
telemetry for the spacecraft orientation, while the time coverage of
the AOCSC is limited due to the bandwidth.
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LSK Files
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),
also known as Barycentric Dynamical Time (TDB).
This archive includes generic text LSK files produced by NAIF,
containing leapsecond information based on the IERS announcements.
The generic text LSK version 0012 contains leap second data up to
and including the January 1, 2017 leapsecond.
The LSK files are provided under the spice_kernels/lsk
directory and are named according to the following scheme:
- generic text LSKs
naifVVVV.tls
where
VVVV is the version; the file with the latest
version supersedes all similarly named
files with earlier versions.
The most detailed description of the data in a text LSK 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
SCLK Files
SCLK (Spacecraft Clock Kernel) files contain on-board clock
calibration data required to perform a mapping between Ephemeris
time (ET) and spacecraft on-board time (SCLK).
This archive includes text SCLK files containing correlation data
for the main Hayabusa2 on-board clock, created by the Hayabusa2
SPICE team from the time calibration table generated by C-SODA,
ISAS.
The SCLK files are provided under the spice_kernels/sclk
directory and are named according to the following scheme:
- main Hayabusa2 spacecraft clock SCLK files
hyb_YYYYMMDD-yyyymmdd_vVV.tsc
where
YYYYMMDD is the file coverage start date
yyyymmdd is the file coverage stop date
VV is the version; the file with the latest
version supersedes all similarly named
files with earlier versions.
The most detailed description of the data in a text SCLK 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
FK Files
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.
This archive includes text FK files defining reference frames for the
Hayabusa2 spacecraft, its structures, and science instruments. These
FKs were produced by the Hayabusa2 SPICE team using the spacecraft
and instrument design documentation as well as actual instrument
alignment values determined pre-launch and as the result of in-flight
calibrations.
The FK files are provided under the spice_kernels/fk
directory and are named according to the following scheme:
- Hayabusa2 mission FK files
hyb2_vVV.tf
where
VV is the version; the file with the latest
version supersedes all similarly named files
with earlier versions, although a SPICE user
might decide decide to use an earlier version
if trying to be consistent with some earlier
computed results.
The most detailed description of the data in a text FK 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
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.
The text MK files are provided under the spice_kernels/mk
directory and are named according to the following scheme:
- Hayabusa2 MK files
hyb2_vVV.tm
when
VV is the version; the file with the latest
version supersedes all similarly named
files with earlier versions.
Multiple versions of a meta-kernel may exist if new kernels were
added to the archive in a later release and the meta-kernel for
that it had to be updated to incorporate them. 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. If more than one meta-kernel file is present, then the
file with the latest version number supersedes all earlier
versions.
(Note that on some environments loading too many kernels at once may
slow down data access.)
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 Hayabusa2 NAV SPKs were included
- the latest 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.
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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
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Reference
=========
For more information about the SPICE system, see documentation and
tutorials available at the NAIF Node of the PDS:
http://naif.jpl.nasa.gov
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Contact
=======
Hayabusa2 SPICE Team
Japan Aerospace Exploration Agency
Institute of Space and Astronautical Science
3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa, 252-5210 JAPAN
email: darts-admin@ML.isas.jaxa.jp
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