An ephemeris (plural, ephemerides) is a table of the
celestial coordinates of an orbiting body computed for regular
intervals of time.
To create a Tabular Ephemeris:
- Click the "Tools" Toolbar button
or select "Tools" from the main menu, then select the "Tabular Ephemeris..." menu option.
- In the Numeric Format panel, select the desired data format.
d = a numeral, mm = arc-minute, ss = arc-second, SGN = zodiac sign.
- Select the coordinates to be computed by clicking items in the list adjacent.
- Select items to be computed by clicking in the Planets box.
- Set the Begin and End entryfields to the limiting
dates of the ephemeris. Set the Step
entryfield to the desired period
between successive positions - by default this is 24 hours.
- As the ephemeris is computed for GMT/Universal Time,
optionally use the GMT
entryfield to input a compensating Time Zone for your location
(NOTE: use '+' for locations east of the Greenwich meridian, '-' for
locations west of Greenwich).
- Optionally to have ephemeris dates in astronomical Julian Date format, check the JD box.
- Click Create
to generate the ephemeris. ZET displays a progress-bar while it is busy.
When done, it displays the message "Created file Ephermerides.txt". Click "OK".
The tabular ephemeris file is held in the file [ZET]\Ephemerides.txt in
the ZET installation folder. If it is desired to retain
a created ephemeris, this file should be renamed. The file can be opened in any text
editing application. The data format is tab-separated columns of plain text.