Overview:This data set contains the System III (1965.0) trajectory and Sun andEarth phase angles of Galileo and selected Jovian moons when Galileo wasinside 30 Jupiter radii from Jupiter. Trajectories are sampled every 20seconds.Coordinates:The Jupiter System III (1965) coordinate system follows the definition ofDr. Alex Dessler in Appendix B of 'Physics of the Jovian Magnetosphere'[DESSLER1983]. This coordinate system is the accepted standard foranalysis of data from the jovian system. System III is a spherical,planetographic coordinate system where the planetary rotation rate of(9h, 55m, 29.71s) is based on the rate of rotation of Jupiter's magneticfield. The prime meridian is defined as the sub-Earth meridian at00:00:00 UT on Jan 1, 1965. Range is measured from the Jupiter center ofmass. Longitude for standard System III is measured west. This directionchoice causes the coordinate system to be left-handed and to a stationaryor distant observer, longitude increases with time.Also included are the Earth and Sun phase angles of each body at eachsample time. Phase angles are the projection of the 3-body angle(Sun-Jupiter-body or Earth-Jupiter-body) into the Jovian equatorialplane. The angle is measured from the anti-Sunward (or anti-Earthward)line, positive in the counterclockwise direction.Sun Phase Angle definition: Sun ^ | noon Jupiter Planetocentric 180 deg Equatorial Projection | | | | Jupiter * * */ * | * (dusk) 270 deg -----------*--|--*------------- 90 deg (dawn) * |\ * * * * | \ | \ | \ |-PA--\ 0 deg body midnightEarth phase angle follows the same convention - simply replace theSun in the diagram above with the Earth.Data Sampling:The data are sampled every 20 seconds inside of 30 Jupiter radii.Data Processing:The trajectory data were created using code written by Steven Joy toextract information from the SPICE (GO-J-SPICE-6-SPK-V1.0) productsproduced by the Galileo project. The software used to create thisephemeris is well tested and in agreement with similar software providedby the Galileo project. All of the SPICE kernels used to produce thisdata set are contained on the Io/J0 MWG archive volume CDROM in theGEOMETRY directory.Data:These data are derived from SPICE kernels produced by the Galileo NAVteam during the mission. All of the SPICE kernels used to produce thisdata set are contained on the MWG archive volume DVD in theEXTRAS/SPICE/KERNELS directory.The kernels (PDS PRODUCT_ID) used to create this were: S980326B.TSP - Prime Mission Reconstruction (JA - E12) S000131A.TSP - GEM reconstruction (E12-E26) S030129A.TSP - GMM (I27-A34) reconstruction, J35 predict PCK00007.TPC - Planetary constants kernel (2000-04-24) MK00062B.TSC - Galileo spacecraft clock kernelAll data are archived in ASCII tables (1 orbit/file). The data files forall orbits contain the following columns:------------------------------------------------------------------------Column Type Description ------------------------------------------------------------------------time char Sample time in PDS time format numberGLL_R real Galileo range from Jupiter  (1 Rj : 71492 km)GLL_LAT real Galileo Jupiter planetocentric latitude GLL_WLON real Galileo System III west longitude GLL_SPHASE real Galileo Sun phase angle GLL_EPHASE real Galileo Earth phase angle IO_R real Io range from Jupiter IO_LAT real Io Jupiter planetocentric latitude IO_WLON real Io System III west longitude IO_SPHASE real Io Sun phase angle IO_EPHASE real Io Earth phase angle EUR_R real Europa range from Jupiter EUR_LAT real Europa Jupiter planetocentric latitude EUR_WLON real Europa System III west longitude EUR_SPHASE real Europa Sun phase angle EUR_EPHASE real Europa Earth phase angle GAN_R real Ganymede range from Jupiter GAN_LAT real Ganymede Jupiter planetocentric latitude GAN_WLON real Ganymede System III west longitude GAN_SPHASE real Ganymede Sun phase angle GAN_EPHASE real Ganymede Earth phase angle CAL_R real Callisto range from Jupiter CAL_LAT real Callisto Jupiter planetocentric latitude CAL_WLON real Callisto System III west longitude CAL_SPHASE real Callisto Sun phase angle CAL_EPHASE real Callisto Earth phase angle Due to their much lower periapsis, the data files for orbits A34 and J35include ephemeris information for Amalthea (semimajor axis 2.5 Rj), andThebe (semimajor axis 3.1 Rj). These files include the followingadditional columns:------------------------------------------------------------------------Column Type Description ------------------------------------------------------------------------AMA_R real Amalthea range from Jupiter AMA_LAT real Amalthea Jupiter planetocentric latitude AMA_WLON real Amalthea System III west longitude AMA_SPHASE real Amalthea Sun phase angle AMA_EPHASE real Amalthea Earth phase angle THE_R real Thebe range from Jupiter THE_LAT real Thebe Jupiter planetocentric latitude THE_WLON real Thebe System III west longitude THE_SPHASE real Thebe Sun phase angle THE_EPHASE real Thebe Earth phase angle Ancillary Data:SPICE kernels MK98264A.TLS (leapseconds), MK98264A.TLS (spacecraftclock), PK96030A.TPC (planetary constants), S980326B.TSP, S991130A.TSP,and S030129A.TSP (spacecraft/planetary ephemeris), and the rotor attitudefile ROT_ATT.TAB located in the GEOMETRY directory of the GOMW_5001volume can all be considered as ancillary data files for this data set.These are the files that were used to generate this data set. Ideally,these data should be generated on demand using the latest SPICE kernelsavailable from the NAIF Node of the PDS.References:Russell, C.T., Geophysical coordinate transformations, CosmicElectrodynamics, Reidel Publishing Co., Vol. 2, 174-196, 1971.Dessler, A. J., Appendix B Coordinate Systems, in Physics of the JovianMagnetosphere, (edited by A. J. Dessler), Cambridge Univ Press, 1983.

These data have been generated by software from the Galileo projectapproved SPICE kernels. The software has been tested extensively andverified using project provided trajectory data sets for some coordinatesystems. Data can be considered to be reliable to the precision impliedby the number of significant digits provided.