Data Set Summary ================ Data Set ID: ULY-J-SPICE-6-SPK-V1.0 Instrument: N/A Instrument P.I.: N/A Data Supplier: C. H. Acton Data sampling rate: N/A Data Set Start time: 1992-01-05T00:00:00.000Z Data Set Stop time: 1995-10-31T00:00:00.000Z Naming convention ----------------- This data set consists of three data files in three separate sub-directories. These files are named according to the convention: *.SPK binary (either PC or Sun) SPICE kernel *.XSP transfer format SPICE kernel Record format ------------- N/A Data column descriptions ------------------------ N/A Missing data flag value ----------------------- N/A Data Description ================ This data set includes the spacecraft trajectory and allied planet and satellite ephemeris (SPK) kernel for the Ulysses 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 1992-01-05 to 1995-10-31 for Ulysses, Jupiter, Callisto, Ganymede, Europa, Io, Earth, the Sun, and the Barycenters for Earth and Jupiter. 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 the version created 1995-06-25. The LSK kernel includes leap seconds through 1996-01-01. 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 the use of the SPK kernel readers. The source file for this particular data set was 92106s.nio. 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 through 9 are planet-satellite system barycenters for Mercury through Pluto respectively. 199 through 999 are planet mass centers for Mercury through 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. Spacecraft are identified using the numeric IDs assigned by JPL's Deep Space Network (DSN), but with a minus sign preceding the number. Thus Ulysses is -55. Parameters ---------- N/A Source Instrument Parameters ---------------------------- N/A Measurement Information ----------------------- N/A 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 Ulysses science instruments.