PDS3_DATA_SET_ID = VG1-S-POS-4-SUMM-L1COORDS-V1.0 DATA_SET_NAME = VG1 SAT EPHEMERIS KRONOGRAPHIC (L1) COORDS BROWSE V1.1 START_TIME = 1980-11-10T00:00:34.923 STOP_TIME = 1980-11-18T22:54:59.149 ORIGINAL_DATA_SET_RELEASE_DATE = 1996-01-01 PRODUCER_FULL_NAME = NESS, N. F.; ACUNA, M. H.; LEPPING, R. P.; CONNERNEY, J. E. P.; BEHANNON, K. W.; BURLAGA, L. F.; JOY, S. P. DATA_SET_SOURCE = NATIONAL SPACE SCIENCE DATA CENTER REFERENCES: Acton, C.H., Ancillary Data Services of NASA's Navigation and Ancillary Information Facility, Planet. Space Sci., Vol. 44, No. 1, pp. 65-70, 1996. Desch, M.D., and M.L. Kaiser, Voyager Measurement of the Rotation Period of Saturn's Magnetic Field, Geophys. Res. Lett., 8, 253, 1981. DATA_SET_DESCRIPTION Data Set Overview ================= Data Set Description -------------------- This data set consists of Voyager 1 Saturn encounter ephemeris data in Kronographic (L1) coordinates covering the period 1980-11-10 to 1980-11-18. Two versions, both covering the same time period, but containing slightly different data, are provided. One version was generated by the Voyager MAG team from Voyager SEDR, the other by the PDS/PPI node using the VG1_SAT.TSP and PCK00006.TPC SPICE kernels. (Note: These SPICE kernels are not currently archived in PDS, but they are available from NASA's Navigation and Ancillary Information Facility (NAIF), https://naif.jpl.nasa.gov/naif/index.html) Due to inaccuracies in Voyager SEDR, as well as changes in the values of some key parameters (e.g. Saturnian radius) the timing is improved for the SPICE generated data. However, since much of the original analysis was based upon the SEDR generated ephemeris, this data has been included as well. SEDR generated ephemeris ------------------------ Data Supplier : NESS, N. F.; ACUNA, M. H.; LEPPING, R. P.; CONNERNEY, J. E. P.; BEHANNON, K. W.; BURLAGA, L. F. Data sampling rate : 96 seconds Data Set Start Time : 1980-11-10T00:00:34.923Z Data Set Stop Time : 1980-11-18T22:54:59.149Z SPICE generated ephemeris ------------------------- Data Supplier : S. Joy Data sampling rate : 96 seconds Data Set Start Time : 1980-11-10T00:00:00.000Z Data Set Stop Time : 1980-11-18T23:58:24.000Z Parameters ========== SEDR generated ephemeris ------------------------ PARAMETER RESOLUTION/ DESCRIPTION NAME UNITS time 96.0 Sec time of the sample (UT) in the format yyyy-mm-ddThh:mm:ss.sssZ m65536 counts spacecraft clock counts mod60 counts fds_line counts sc_x R[J] kronocentric (L1) cartesian sc_y R[J] cartesian position vectors: X, Y, and sc_z R[J] Z vel_x km/s kronocentric (L1) X, Y, and Z spacecraft vel_y km/s velocity components vel_z km/s sc_r R[J] kronocentric (L1) spherical sc_lat degrees coordinates position vectors: range, sc_lon degrees latitude, and longitude CartSys3_to_SphSys3 cartesian L1 coordinates to spherical L1 coordinates rotation matrix containing 9 1pe15.8 elements SC_to_CartSys3 payload (spacecraft) to cartesian L1 coordinates rotation matrix containing 9 1pe15.8 elements SC_to_SphSys3 payload (spacecraft) to spherical L1 coordinates rotation matrix containing 9 1pe15.8 elements SPICE generated ephemeris ------------------------- PARAMETER RESOLUTION/ DESCRIPTION NAME UNITS time 96.0 Sec time of the sample (UT) in the format yyyy-mm-ddThh:mm:ss.sssZ R AU kronocentric (L1) spherical coordinates LAT degrees range, latitude, and longitude position LON degrees LocTime hours angular separation between the meridian containing the sun and the one containing the spacecraft converted to a time. The sun meridian is defined to be noon (12.000), with midnight (0.000) opposite it. Dawn (6.000) and dusk (18.000) are where the sun rises and sets according to the planet's rotation Coordinate System ================= The Kronographic (L1) coordinates is a Saturn centered spherical system, based on the Saturn Longitude System (Voyager Measurements of the Rotation Period of Saturn's Magnetic Field, Desch and Kaiser, JGR, 8, 253, 1981). In this coordinate syatem, longitude increases with time as viewed by a stationary remote observer. In cartesian coordinates: X points along the Saturn-Sun line in the solar equatorial plane (positive towards the Sun) Y completes the right handed set Z points along the Saturn's spin axis, positive In spherical coordinates: R Saturn to spacecraft range (positive away from Saturn) LAT completes the left handed, orthogonal set LON east longitude (with longitude increasing eastward from a specific Saturnian prime meridian) SPICE ephemeris were generated using the current definition of the Saturnian radius, 60268 km. The spin rate used in generating these data is the same as that used for System III (1965), +870.536 degrees/24 hours. CONFIDENCE_LEVEL_NOTE = Confidence Level Overview ========================= SPICE generated ephemeris ------------------------- The SPICE generated data were derived from SPICE using software that has been extensively tested. They should give as accurate representation of spacecraft ephemeris as possible using these kernels. Comparisons between these data and other data from previous Saturn missions should be performed with caution. Some key parameters, such as the Saturnian radius, have changed from mission to mission. Definitions for Saturn's spin rate and the orientation of its spin-axis have also changed slightly since the early Pioneer days. Data Coverage ============= Filena0me Records Start Stop ------------------------------------------------------------------- Volume ID: VG_1601 SEDR_L1.TAB 7844 1980-11-10T00:00:34.923Z 1980-11-18T22:54:59.149Z SPICE_L1.TAB 8100 1980-11-10T00:00:00.000Z 1980-11-18T23:58:24.000Z Missing Data Flag ================= Any SEDR generated ephemeris data column of value -9.99999999, -99.99999999, or -999.99999999 is a missing data flag.