Dataset Overview:

This dataset contains the Galileo spacecraft trajectory during the Earth
1 flyby. The data have been derived from SPICE kernels at a 1 minute sample 
rate. The data are provided in both  Geocentric Solar Ecliptic (GSE) and 
Geocentric Solar Magnetic (GSM) coordinates and are given in units of earth 
radii where 1 Re = 6378 km.


    Data Columns:

    time   S/C event time (UT) given in seconds since 1966
    scet   S/C event time (UT) given in the form yyyy ddd mon day hh:mm:ss.sss
    X      S/C position X component in GSE or GSM coordinate <Re>
    Y_gse  S/C position Y component in GSE coordinates <Re>
    Z_gse  S/C position Z component in GSE coordinates <Re>
    Y_gsm  S/C position Y component in GSM coordinates <Re>
    Z_gsm  S/C position Z component in GSM coordinates <Re>
    

Coordinate Systems:

The Galileo trajectory data are being archived in 2 coordinate systems.
Geocentric Solar Ecliptic (GSE) and Geocentric Solar Magnetic (GSM) are 
related earth centered coordinate systems. Both the GSE and GSM X directions
are taken along the Earth - Sun line, positive towards the Sun. The GSE
Z direction is parallel to the ecliptic normal, positive northward, and
Y completes the right-handed set (towards dusk). For GSM, the X-Z plane
contains the Earth's dipole moment vector, positive northward, and Y completes
the right-handed set. GSE coordinates are commonly used for analyzing the
solar wind near the Earth and GSM coordinates are used when analyzing data
inside the Earth's bow shock.

Data Processing:

These data have been derived from the PDS dataset:

"GO-J-SPICE-6-SPKV1.0"

The SPK file used to dervied this product was:

"GL_LONG2.BSP"

Data Quality:

The data have been derived from the Galileo SPICE kernels using well tested
software from the SPICELIB and GLLSPICE subroutine libraries. Each data point
is computed using S/C and planetary ephemerides computed at the time of the
dataset sample (not interpolated).