Target Acquisition and Guiding with MAESTRO
Last update: May 30, 2013
1. Internal Guide Camera
MAESTRO has an internal guide camera for target acquisition, which
looks at the slit plate. The field of view is small but echelle
targets are generally bright. Bring good coordinates and it
should be relatively easy to acquire even a faint (m~16-17) target in
full moon. We have limited experience with using MAESTRO in
dark time, so the faint limit of the guide camera is not well known at
this time.
The internal guide camera is a "Lesser-Gary Schmidt" camera built by
ITL. In a pinch, it can be run by VNC-ing into the guide camera
computer and using the usual AZCAM interface. It can also in
principle be used to guide, but there is not likely to be another star
on the slit plate to use as a guide star. This camera should be
used for guiding only as a last resort. Spilled light guiding on
the slit is not recommended (we want all the light going down the slit
after all).
2. Off-Axis Guiding
As of May 2013, we guide by using the f/5 off-axis guide camera called
Stellacam. Detailed instructions for the acquisition of targets
and off-axis guiding, written by Richard Cool and Johanna Teske, can be
found here:
https://docs.google.com/document/d/10qzwfR9gP3FLdjkabHKIVbsR_MuotA0_55p8eRKXWcw/edit
with a PDF version here.
Notes:
- The off-axis guide camera has a limited patrol field and finding
a suitable star to guide on requires setting the spectrograph to a
specific position angle. Since we have the f/5 ADC, the choice of
position angle should have no impact on observing. However,
observers who want to observe their targets at a specific position
angle for scientific reasons should contact Jill Bechtold or Richard
Cool todiscuss their observations before proposing for telescope time.
- Non-sidereal tracking and guiding is fully implemented.
3. Off-Axis Wave-Front-Sensing
We plan to use the f/5 camera for wave-front-sensing off-axis, so that
WFS corrections can be derived and applied without interrupting science
exposures. Until off-axis wave-front sensing is implemented, the
observer will have to stop observing as necessary and have the operator
carry out the usual WFS routine with a bright star on-axis.
4. Obsolete instructions are here