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.