Index
Date set_date(source, utc, horizon)
Return the nearest date and time at which a given source sets.
- Arguments:
-
Source source
- The source to describe.
Date utc
- The date and time around which to search for the set time.
Elevation horizon
- The elevation of the local horizon to be used when
calculating the set time.
Example:
The following example displays the date and time at which Jupiter
will set or already set below 43 degrees. If Jupiter doesn't set
for more than 12 hours, the previous set time is shown. If
Jupiter doesn't set at all, the zero point of Modified Julian
Date (17-Nov-1858) is displayed.
print $set_date(jupiter,$date(),43)
Example:
The following examples is used to switch to a 3c273 in time to
use it as a calibrator 10 minutes before it sets.
Date stop_time = $set_date(3c273,$date,-2) - 15m
catch $date >= $stop_time {
...primary observations...
} {
print "Doing calibration on 3c273 before it sets in 10 minutes."
track 3c273
until $elapsed > 10m
}
Martin Shepherd (21-Aug-2000)