Solar System objects move at non-sidereal rates and cannot be tracked by
specifying a single position. At the FCRAO, the ephemerides of the SUN,
MOON
and all planets
,
are
maintained on-line,
and these objects may be tracked by simple entering the name of the object.
Thus, to track VENUS, one simply enters:
VENUS
to initiate the Venus tracking program.
On rare occasions, the date coverage of the ephemeris may not be adequate to track the object. The command PLANET allows the user to check the date coverage and verify that the proper ephemeris information is on line. If the date range is not correct, then the ephemeris files need to be updated with the EPH utility program. See Chapter 5 for a complete description of this procedure.
It is also possible, using the EPHEM3 utility program, to generate an ephemeris by specifying two body orbital elements. Since this capability has been used historically for cometary observations, the command COMET is used to initiate tracking of the object. Interested observers should see the full description of the EPHEM3 program in Chapter 5 of this manual.