PDS_VERSION_ID = PDS3
RECORD_TYPE = STREAM
OBJECT = TEXT
PUBLICATION_DATE = 1998-05-01
NOTE = "DATASET.TXT contains the data set description."
END_OBJECT = TEXT
END
Data Set Summary
================
Data Set ID: VG1-J-SPICE-6-SPK-V2.0
Instrument: N/A
Instrument P.I.: N/A
Data Supplier: C. H. Acton
Data sampling rate: N/A
Data Set Start time: 1979-02-05T23:59:59.999Z
Data Set Stop time: 1979-04-08T23:59:59.998Z
Record format
-------------
N/A
Data column descriptions
------------------------
N/A
Missing data flag value
-----------------------
N/A
Data Description
================
Version 2.0
-----------
This data set replaces the Voyager 1 Jupiter SPICE data set
(DATA_SET_ID = VG1-J-6-SPK-V1.0).
Data Set Description
--------------------
This data set includes the spacecraft trajectory and allied
planet and satellite ephemeris (SPK) kernel for the Voyager 1
Jupiter encounter, plus copies of the generic planetary
constants (PCK) kernel, and the leap seconds (LSK) kernel. The
SPK kernel provides ephemeris information for the period
1979-02-05 to 1979-04-08 for Voyager 1, Jupiter, Metis,
Adrastea, Thebe, Amalthea, Callisto, Ganymede, Europa, Io,
Earth, Moon, the Sun, and the Barycenters for all nine major
planets. This file is provided in both PC binary (EBCDIC) and
IEEE (Sun) binary format. The PCK kernel contains information
specifying Jupiter's size, shape, and orientation. The LSK
kernel is used for transforming between ephemeris time, the
time system used in the SPK and PCK files, and UTC time (also
referred to as Spacecraft Event Time or SCET). Both the PCK
and LSK kernels are provided in ASCII format.
The PCK kernel is PCK_version 00003 (1990-06-25). The LSK
kernel includes leap seconds through 1991-01-01. Information
regarding the SPK version and contents are detailed below.
This data set is a NAIF SPK file, which is the realization of
the SPICE S and P-ephemeris kernels. The SPICE S kernel is the
logical component of the SPICE kernel concept which contains
spacecraft trajectory data (position and velocity in a
Cartesian reference frame). The SPICE P-ephemeris kernel is
the logical component of the SPICE kernel concept which
contains target (one or more of planet, satellite, comet,
asteroid) ephemeris data (position and velocity in a Cartesian
reference frame).
NAIF provides a software toolkit, called SPICELIB, containing
the Fortran 77 source code subroutines which a user needs to
read SPK files. Those intending to use SPK kernel files should
order this SPICELIB toolkit from the PDS (if it is not already
on hand) and integrate appropriate modules into their own
applications program. Users should NOT attempt to write their
own software to read SPK kernels files.
SPICELIB software is highly documented via internal headers,
and some additional documentation is available in separate
SPICELIB ASCII text files called Required Reading files. The
SPK Required Reading File, identified as SPK.REQ, describes
use of the SPK kernel readers.
This particular data set is a merge of five SPK source files.
Four of these (T790210, T790213, T790303, and T790318) were
made from standard Voyager NAV Team archival products which
were made for SEDR production. The fifth source file was
(JUP024_VGR) made from a post-encounter satellite ephemeris
file which contains ephemeris data for satellites which were
not included in the standard Voyager NAV Team archival
products. These source files are summarized below.
NAIF_ID FOR EACH
BODY INCLUDED
NAV ID START TIME STOP TIME (See key below)
--------------------------------------------------------------------
T790210 1979 FEB 06 00:00:00 1979 FEB 13 00:00:00 1 thru 10, 301,
399, 501 thru 505,
599, -31
T790213 1979 FEB 13 00:00:00 1979 FEB 19 00:00:00 1 thru 10, 301,
399, 501 thru 505,
599, -31
T790303 1979 FEB 19 00:00:00 1979 MAR 03 00:00:00 1 thru 10, 301,
399, 501 thru 505,
599, -31
T790318 1979 MAR 03 00:00:00 1979 APR 09 00:00:00 1 thru 10, 301,
399, 501 thru 505,
599, -31
JUP... 1979 FEB 01 00:00:00 1979 NOV 03 00:00:00 505, 514 thru 516,
024_VGR 599
NAIF body IDs are used within SPICE kernels to label data for
a specific body. These IDs must be employed as arguments in
the SPICELIB SPK kernel readers.
Users might note that not all those bodies for which data are
available in this file are listed in the Data Set Target
Template below.
Key to NAIF_IDs:
1 thru 9 are planet-satellite system barycenters for Mercury
thru Pluto respectively.
199 thru 999 are planet mass centers for Mercury thru Pluto.
10 is the SUN.
nxx are satellites, where n is the parent planet number. Thus,
n=3 for Earth, n=4 for Mars, n=5 for Jupiter, etc. Satellites
which may be found in this particular SPK file are:
501=IO, 502=EUROPA, 503=GANYMEDE, 504=CALLISTO, 505=AMALTHEA,
514=THEBE, 515=ADRASTEA, 516=METIS.
Spacecraft are identified using the numeric IDs assigned by
JPL's Deep Space Network (DSN), but with a minus sign
preceding the number. Thus Voyager 1 is -31 and Voyager 2 is
-32.
Processing Level Id : 6
Software Flag : Y
Processing Start Time : 1987-03-26
Processing Stop Time : 1989-08-29
Parameters
----------
N/A
Source Instrument Parameters
----------------------------
N/A
Measurement Information
-----------------------
N/A
Processing
----------
Processing History
------------------
Source Data Set ID : NAIF 18
Software : SPICELIB
Product Data Set ID : VG1-J-6-SPK-V1.0
Source Data Set ID : NAIF 19
Software : SPICELIB
Product Data Set ID : VG1-J-6-SPK-V1.0
Source Data Set ID : NAIF 20
Software : SPICELIB
Product Data Set ID : VG1-J-6-SPK-V1.0
Source Data Set ID : NAIF 21
Software : SPICELIB
Product Data Set ID : VG1-J-6-SPK-V1.0
Source Data Set ID : NAIF 121
Software : SPICELIB
Product Data Set ID : VG1-J-6-SPK-V1.0
Software 'SPICELIB'
-------------------
SPICELIB contains hundreds of ANSI FORTRAN 77 source code
subroutines and functions for calculating instrument
observation geometry. This software is intended to be
integrated into a user's own science analysis application
programs. Included in this library are readers for the SPICE
kernels, which are the principal data sets used in computing
instrument viewing geometry, or for planning data taking
sequences.
Additional software is available for then computing such
items as latitude, longitude, phase angle, and emission
angle of an instrument's principal point, or nearly any
other geometric parameter of interest.
Software Name : SPICELIB
Software Type : NIN
Software Release Date : 1990-02-05
Node ID : NAIF
Cognizant Engineer : CHARLES H. ACTON
Software Access Description : NOT ACCESSIBLE THROUGH PDS
CATALOG - CONTACT PDS/NAIF NODE
Note that this is not the official archive for these SPICE
kernels. The PDS/NAIF node plans to officially archive these
data on a separate volume. These data are provided here for
use with software designed to generate trajectory or perform
coordinate transformations.
To learn more about SPICE, or for information about how to
acquire the official archive version of these kernels, or the
SPICELIB software, please contact Charles H. Acton of the
PDS/NAIF node (INTERNET: cacton@spice.jpl.nasa.gov, DECNET:
NAIF::CACTON, PHONE: (818)354-3869 ) or check the PDS
website's (http://pds.jpl.nasa.gov/) link to the NAIF node for
current NAIF contact information.
Confidence Level Overview
-------------------------
There is essentially no loss in accuracy when an SPK file
is made from one or several NAV source files.
Statistics on ephemeris accuracy are not available, but
errors are very small compared to normal uncertainties in
reconstructed pointing knowledge for the Voyager science
instruments.
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