Ephemeris File
The ephemeris file is an ASCII file with the following structure
1) Generation Dates
The first line of every file contains a Generation Date
For example : Generation Date=Tue Mar 10 13:51:57
1998
2) Ephemeris records
The lines after the generation date are the ephemeris records, and
definition of the record items are described below
Ephemeris Record Structure
1.0 Time block
| Name | Description | Type | Size | Column offset |
| UTC | UTC time | short | 5 | 1 |
| ET | Ephemeris time since J2000 | double | 1 | 6 |
| Name | Description | Type | Size | Column offset |
| GAL_JSA | x,y,z position of Galileo | float | 3 | 7 |
| GALV_JSA | velocity of Galileo (km/s) | float | 3 | 10 |
| CAL_JSA | x,y,z position of Calisto | float | 3 | 13 |
| EUR_JSA | x,y,z position of Europa | float | 3 | 16 |
| GAN_JSA | x,y,z position of Ganymede | float | 3 | 19 |
| IO_JSA | x,y,z position of IO | float | 3 | 22 |
| COROT_JSA | corotation vector (unit vector) | float | 3 | 25 |
3.0 System III Dipole Coordinate
Distance unit in Rj (Rj = 71492.0 km)
| Name | Description | Type | Size | Column offset |
| GAL_JMA | x,y,z position of Galileo | float | 3 | 28 |
| GALV_JMA | velocity of Galileo (km/s) | float | 3 | 31 |
| CAL_JMA | x,y,z position of Calisto | float | 3 | 34 |
| EUR_JMA | x,y,z position of Europa | float | 3 | 37 |
| GAN_JMA | x,y,z position of Ganymede | float | 3 | 40 |
| IO_JMA | x,y,z position of IO | float | 3 | 43 |
| COROT_JMA | corotation vector (unit vector) | float | 3 | 46 |
4.0 Joviancentric Solar Ecliptic Coordinate
Distance unit in Rj (Rj = 71492.0 km)
| Name | Description | Type | Size | Column offset |
| GAL_JSE | x,y,z position of Galileo | float | 3 | 49 |
| GALV_JSE | velocity of Galileo (km/s) | float | 3 | 52 |
| CAL_JSE | x,y,z position of Calisto | float | 3 | 55 |
| EUR_JSE | x,y,z position of Europa | float | 3 | 58 |
| GAN_JSE | x,y,z position of Ganymede | float | 3 | 61 |
| IO_JSE | x,y,z position of IO | float | 3 | 64 |
| COROT_JSE | corotation vector (unit vector) | float | 3 | 67 |
5.0 Moon Center Coordinate
The definition of the Moon Center Coordinate is as follow. The Z-axis
is the System III Z-axis.
The Y-axis is the corotation vector at the moon. X-axis is just YxZ.
| Name | Description | Type | Size | Column offset |
| GAL_CAL | x,y,z position of Galileo in Calisto center coordinate. Distance unit in RCalisto (RCalisto = 2403 km) | float | 3 | 70 |
| GALV_CAL | velocity vector of Galileo in Calisto center coordinate. (km/s) | float | 3 | 73 |
| GAL_EUR | x,y,z position of Galileo in Europa center
coordinate. Distance unit in REuropa (REuropa =1565 km) |
float | 3 | 76 |
| GALV_EUR | velocity of Galileo in Europa center coordinate. (km/s) | float | 3 | 79 |
| GAL_GAN | x,y,z position of Galileo in Ganymdede center coordinate. Distance unit in RGanymede (RGanymede = 2634 km) | float | 3 | 82 |
| GALV_GAN | velocity vector of Galileo in Ganymede center coordinate. (km/s) | float | 3 | 85 |
| GAL_IO | x,y,z position of Galileo in Io center coordinate. Distance unit in RIo (RIo = 1830 km) | float | 3 | 88 |
| GALV_IO | velocity vector of Galileo in Io center coordinate. (km/s) | float | 3 | 91 |
| Name | Description | Type | Size | Column offset |
| GALV_SC | velocity of Galileo (km/s) | float | 3 | 94 |
| CAL_SC | x,y,z position of Calisto | float | 3 | 97 |
| EUR_SC | x,y,z position of Europa | float | 3 | 100 |
| GAN_SC | x,y,z position of Ganymede | float | 3 | 103 |
| IO_SC | x,y,z position of IO | float | 3 | 106 |
| COROT_SC | corotation vector (unit vector) | float | 3 | 109 |
| JUP_SC | x,y,z position of Jupiter | float | 3 | 112 |
| SUN_SC | x,y,z position of Sun | float | 3 | 115 |