for large zenith angles (similar effect and correlation like for the
Whether the stabilising takes long, depends on the direction from which
the telescope is approaching the tracking position.
quality of tpoints
to take a good tpoint make sure that
the tracking has stabilized
the leds have an appropriate brightness
the leds are recognized correctly, i.e. the cross marks the center
of the led spot (moonlight can affect this)
the circles are there and not jumping
the leds are not saturating (happens in some pictures)
only for tpoints:
the star is reconized on the camera lid, i.e. marked by a green cross
(moonlight can affect this)
the green cross is in the middle of the spot of the star
at least 5 leds are recognized
only for starguider tpoints:
the mispointing is < 5 min
the tpoint taken before has good quality
at least 3 leds are recognized
Every time a tpoint is stored, an according output is written to
the shell. (see first picture)
If the time between tpoint and starguider tpoint is > 1 minute, the
starguider tpoint is not stored (see output in the shell), and tpoint +
starguider tpoint have to be repeated
The values, which are stored, belong to the picture, that appears,
when the button gets released. This means, that the tpoint has to be
repeated, if this picture is bad. Please put a note in the runbook
in this case.
Too much moonlight, can make a tpoint impossible.
You can avoid waiting time for the tracking to stabilise, when you
are approaching the position of the star, from that direction, from
which the star was coming on its path across the sky.
As the software was not intended to handle switching between the
cameras, this procedure is quite unstable. Due to that the Software
might crash or hang. Please restart it in this case and start tracking
the star again. Another possible effect of the instability: The
longer the program runs, the slower the switching might get.
The mispointing values in the starguider are relative values, as
the starguider is not yet calibrated. The purpose of the starguider
tpoints is to do this calibration.
after taking tpoints:
make sure that
you switched back to starguider mode
the 'STAR' button in the AMC program is deactivated (focal length
adapted to focus point source in 10km distance onto the entrance of the