BOK 2.3m on Kitt Peak Operating Procedures
written by: David Cook
stjukshon (2 monitors)
-IRAF and viewing images
galil (Windows Machine)
-(exposure time, file location, image type, etc...)
The accepted catalogs are of a DOS format, yes really. I have a perl script that
changes a text file into the correct format. However, it does not currently work
fully -> work in progress.
Once you have a correctly formatted catalog you have to upload it to the operators terminal:
Generally everything is kept running at all times, if not or if everything freezes, follow
the steps below:
There are 2 AzCam tool icons, a one chip called "AzCam90primeOne" and a four chip "AzCam90Prime".
I use the the one chip configuration.
start the "AzCam" tool by double clicking the icon. This brings up 2 windows: the status/server
and the gui which controls the ccd.
In different terminals type:
On the gui:
-Click "Read Filters" and wait until the central messages say all is well
-Click "Initialize Wheel" and WAIT patiently (about 1 min) until the central messages say all is well
- The "Wheel Moving" indicator goes off and on several times during this step,
so don't get trigger happy with button pushing.
-Hit the filename button and add the correct directory on stjukhon where the images are to be stored
Change the "Image Type" on AzCam to "zero", this shuts the shutter, but you will need to enter an
exposure time of 0. In "filename" pick what you want to call your biases, I usually call them "b".
Then enter the starting number, usually 1. This will call your baises b0001,b0002... and so on.
Change the "Image Type" on AzCam to "flat". The counts you are looking for on your flat
image is between 5,000 and 20,000 counts. Also, the shutter system on the camera is very
good and allows good images down to 0.01 seconds. So once you get a good image at 0.01 seconds
you can do a sequence and it will nicely take images for you, usually at the correct counts
if you time it right.
I have been told there is no dark current in 10 min images. But if you want to take them it is very
similar to the procedure for flats and biases.
If the "current filter status" is yellow, then the filter is loaded and good to go; if this is green then no
filter is loaded. If you want to change the filter: unload whatever filter is in there, click on the
desired filter and hit select. the gui tells you which filter is passing by the filter position. Then
when it says your filter is ok, you hit load and wait for it to become yellow.
1. "Nominal Plane" (this aligns the actuators so CCD is perpendicular
to the beam). Hit it a couple of times.
2. Use AzCam to do a focus sequence.
The new focus sequence resets focus values back to
the starting value after the sequence is finished.
3. Tell the galil how much to move the actuators, just like before,
EXCEPT please type the same number into all 3 spots (and don't
use the "lock" button for now... with the old gui
you could just type into actuator B and use "lock"- please
don't do that now until we fix a couple of routines
that depend on the state of this button)
Hit the "Focus" button and the actuators will move that amount.
Take a short exposure and ensure that this is good focus.
If so, hit "Set Reference". NOTE, we only poll the Galil every
2 seconds so don't expect any updates FROM ANY GUI ACTION
faster than that.
4. Expose using AzCam
5. At end of each exposure, hit "Restore Focus" which will
take out flexure by moving the LVDTs to the reference values.
Hit the button a couple of times.
6. The next time you want to focus, start at "Nominal Plane"
and go through this sequence.
There is a rack to the left of the observing desk that contains the computer to stjukshon. There is a fold
down access area with a USB port to load your images. Or you can just sftp onto it to put it on your computer:
Humidity - 85%
Wind - Sustained 40 MPH winds
Full well is 125,000 electrons or roughly 50,000 data numbers. CCD is linear to that point. I think
the overscan level is about 1000 so staying below 45000 must be safe.
gain is 2.5 electrons/data number
Noise seems to be 7 electrons in overscan region and 10 electrons in the active imaging area. So 10
is the number you want.
Readout time plus file creating time is 19 or 20 seconds. we're reading through 4 amps.
Pixel Scale - 0.45 arcsec/pix