Observing Checklist for Imaging
with 24" Telescope Using CCDAuto (linux machine)
Unix commands are shown in italics.
Commands in the ucirob program are in red.
Commands in the CCDAuto program are in blue.
Commands in Xephem/SkyView are in green.
- The computer-controled AC power unit should be cycled on/off
up ucirob. That's the red lighted power switch beside the large
on the front of the black box in the rack.
- If it is off, turn on the power strip that lies on top of the red
tool bench. This powers the CCDs, and sometimes we turn it off if they
are not used for a significant period of time just to prevent possible
- Log onto ucirob.ps as observer.
- Create your own directory for that night with mkdir, cd
it and make subdirectories named images, flats, darks.
- Start ucirob.ps from your directory.
- Open Obs.
and when completed (see message
screen) make sure the mirror covers are indeed all the way open.
the one facing South does not open all the way. If it is closed then
the ladder and gently open it.
- Power up the CCDs (CCDs
- Start CCCAuto program (FILE/Start
- Start up the ST9 - Imaging CCD (Cameras/Imaging CCD/Establish
- Set the operating temperature to no less that 25 degrees C below
CCD/Turn on Temp Reg
and enter the temp in degrees C). Check that the power doesn't exceed
once the operating temp is reached. If it does you must raise the temp.
If the dessicant in the camera has not been baked lately, the CCD
may frost over if the humidity is high and the operating temperature is
low. You'll notice it as a large scale pattern on the CCD image,
to fog on your bathroom mirror. If frost occurs, raise the temp (turn
temp reg) and take images until you find a temp that works. Remember
lower the operating temp is the lower the dark count and noise will be.
- Take a test image (Execute/Expose Singe Frame then Execute)
to verify the ST9 is working.
- Start Xephem (FILE/Start
- Open the SkyView window in Xephem (View/SkyView
- The scale button on LHS menu changes coords to RA/DEC in SkyView.
- Toggle Live Report (top button on RHS) to get cursor readout of
- In Xephem 's SkyView bring up the Telescope/Configure panel,
it should read "lx200xed" and "queue". Click on Show
Sky View Marker. Click
Then click on OK
in the status window that appears -- don't forget to do this because it
completes the link between Xephem and ucirob.
- Plot the CCD Field-of-View in Xephem's SkyView by: (1) pulling
-> eyepieces - > ST9 (or whatever CCD it is), click Use then
close the window, and (2) right click
and select Place
- In Xephem's SkyView, put cursor on an object and right click to
on it. Right click, and hold down right button to Center
and Zoom on the object. To slew the telescope to it, right
click and hold the right button down and slide to Telescope
- Move to a bright star near where you plan to observe, such as
varify the pointing of the telescope. Center the star in the field of
view (CCD or eyepiece, but not the cente r of the CCD FOV is lower and
to the left of the eyepiece FOV.). Check the small finder scope and
make sure the star is centered in it, too. Reset home coordinates in
ucirob, if needed (only do this if you are sure you know what you're
- Focus the telescope for the ST9 CCD. First, select the V-band
filter in the CCD. Note that if you do not, it is likely in the
"clear/open" position which does not have the same focus as when you
are observing through a filter. Choose a bright star in
Xephem that is located near the first object you plan to observe. Slew
the telescope to it. Switch to the V-band filter and take a series of
images of a
star at different
settings and measure the FWHM and Peak Flux for each to find the best
i.e. the focus setting that gives the smallest FWHM, highest Peak Flux,
and the smallest scatter around a Gaussion-shaped radial profile. Find
a star bright enough to record > 1000 ADU at peak in a 3 to 15 sec
Note that you can change filters to increase/decrease fluxes (all the
are parfocal). The minimum time of 3 sec will allow you to sufficiently
average over temporal variations in the seeing caused by the
fluctuations. Use a focus step size of ~15 units, and plan to try
5 to 7 focus values. Step through focus values monotonically
always decreasing or increasing) because there is some backlash in the
motors when you change directions, and hence you want to avoid it.
Focus, enter a new focus value for the T Axis and
Leave the TUV axes linked so that
all three motors attached to the secondary will move by the same
(You would only unlinks them to change the collimation of the secondary
mirror, but this should only be done by one of the professors!) Take an
image with the ST9 with Expose. Click on Show
Plot then click on the star. Record the FWHM and Peak
Flux and note
the size of the scatter around the radial profile fit. Repeat for the
of focus values and determine the best focus. Move the focus to ~150
above/below the best focus and then back down/up to the best focus (to
mitigate errors due to backlash). You may have to refocus periodically
if the temperature changes greatly or as you move to different
in the sky. Best focus is T = -5560, U = -5785, V = -5620 for the
ST9 CCD for a temperature inside the dome of T = 22 deg C when
recollimation was last done in June, 2005.
- If you want to use the finder/guider telescope (optional),
initialize the guider CCD. Under Finder,
click on the Settings
button. Click on Link.
It will initially fail claiming it can't set the video head offset.
on Link again
and it will initialize properly.
Set the operating temperature to no less than 20 degrees C less
the ambient temp and click on Temp Reg.
the desired exposure time (seconds), binning (1x1) and hit Apply.
Click on Expose
to take an image.
- Mark the ST9 FOV on the guider image by clicking on ST9
Frame button. To move the telescope so that a certain
in the guider image is moved to the center of the ST9 FOV, right
click on the object and tell the telescope to move. To reset the
default center of the ST9 FOV, click on an object in the guider
which lies at the center of the ST9 image, left click on the
which enters the Star PSF values of xc, yc, hwhm (although
hwhm is incorrect) then click on ST9 Center.
Turn the ST9
Frame off and on to redraw the frame at the new center. Note
that the current default ST9 center is (x,y) = (156, 77).
- Field Sizes and Orientations:
To begin guiding on a star in the guider FOV, first take an image
make sure there is one in the field and define the needed exposure
The star should have a maximum flux in the center pixel of a few
ADU. In the ucirob window, enter Guiding/AutoGuiding
Settings to open the Autoguiding Parameters window. Set the
time and the interval between downloading an image and taking the next
image. Use a minimum of 10 sec as the interval. Hit Apply then click On
to take the first image. The
main ucirob window will tell you to left click on the star you want to
then hit Select
in the Current Guide Image
window. Then it will take repeated images of a small subregion of the
surrounding that star. It will automatically send small slew movements
to the telescope to keep you centered on that star. Unclick On in
the Autoguiding Parameters window to stop guiding.
When taking images with the ST9, to take another with the same
time just click on Take
Exposure in the Current
Image window. To change exposure time or force a new dark image to be
you must pop up the Single Exposure Settings window (Exectue/Exposure
Single Frame). Remember to click on Apply after
you change exposure time, etc. before hitting Execute.
Remember to turn off the guider before slewing to a new object.
Shutting Down the Observatory
- ST6 FINDER CCD: North is Up, and
to the Left with the origin at top, left-hand cornor of the
that there are two bad pixels that lie at (x,y) = (221, 168) and (239,
108). Do not confuse them with stars.
- ST9 SCIENCE CCD: FOV = 6.9' x 6.9'.
North is Up, and East to the Right with
origin at the top, left-hand cornor of the display.
- 40mm EYE PIECE: center of the ST9 FOV is
in radius outward from the center of the eyepiece FOV roughly along the
CCD/Turn off temp reg, Close
Link then File/Exit.
- In ucirob, under Finder/Settings
temp reg, and under Power Up turn off the CCDs
- In Xephem 's SkyView bring up the Telescope/Configure panel and
Then click on OK
in the status window that appears. Then Exit Xephem.
- Close Obs
- Exit ucirob.
- Log off the computer and turn off the monitor, but DO NOT turn
computer. We leave it on so that anyone can log in remotely from any
machine and operate the telescope.
- If something goes wrong, call Profs. Smecker-Hane. Do not
leave the telescope/ucirob if you are not sure the shutter is closed
If you run into a problem, you can call Profs. Tammy Smecker-Hane
@ work, 509-7195 @ home).
If you need to reboot ucirob:
If ucirob crashes you may need to reboot the
machine. You can't simply reboot the computer because the computer will
random signals to the rack. If you do, you're likely to get random
of both the shutter, dome and lights! Instead follow this sequence:
- Turn off the power to the rack (red button on top of rack) and
the power to the AC controllable outlet box (red button on the middle
box in the rack) .
- Reboot the computer.
- Enter ucirob, which will set the state of the electronic input to
Then exit ucirob.
- Turn the rack and AC controllable outlet box back on.
- Restart ucirob. Send the dome to the home position (Observatory/Send
Home) to make sure its properly initialized.