2.7-m apogee guider manual
Personal Reference Notes
Prepared by Tom Barnes
(last updated March 25, 2005)
Note: Use your own computer account rather than the "tgb" account wherever it
appears. Also note that setup here is defined for CS2x, but the basic guider operation is the same for all instruments. Also, please check the magnetic board in the control room above and to the right of oberon's rightmost monitor to see which apogee computer (apogee or apogee2) you should be using.
Autoguider Operation
- The autoguider is controlled through the apogee system using its own computer.
SET UP
- Turn on the Th-Ar for illumination.
- Move the Lamp Stage to cs2
- Move the Guider mirror to Slit
- In an Oberon window,
- % xhost +apogee
- % ssh -l tgb apogee (that is a minus ell)
- [tgb@apogee] setenv DISPLAY oberon:0.n where n=0,1,2 for left, middle, right display
- [tgb@apogee] cagdr to launch guider window
- In the apogee window that comes up,
- At the far right, click the box in a box symbol to launch the control panel. This is used for zooming.
- From the Expose menu item,
- Launch Guider window
- Launch Single exposure mode – should see slit in Th-Ar light.
- Adjust exposure time as needed in the Guider window.
- Draw the outer box – to cover all the slit reflecting area.
- Zoom in to the slit area.
- The image may be centered by putting the cursor on the center of the slit and clicking the center mouse button.
- Draw the inner box – this is the region within which guiding occurs.
- From the Markers menu,
- Set Fiducial - a purple cross at the slit center
- Move the Guider mirror to Field
- From the Markers menu,
- Set Primary - a red cross at the slit position in the field.
- There are other options for these markers.
- Turn off the Th-Ar lamp.
- In the Guider window,
- Set the correction percentage used (80% during acquisition, 15-20% during guiding)
- Verify 3 sigma over sky for centroid
- Verify Gauss 2d
- Verify Find Stellar Photometry
- Set Display update fiducial
- [The FHWM strip chart window and the Flux strip chart window may be useful.]
USE
- When a target appears in the field,
- Use the handpaddle to move it into the inner box.
- Switch the Guider mirror to slit.
- In the Guider window,
- Enable autoguiding
- Click start (at the bottom of the window)
- Adjust integration time as needed (at the top of the window)
Observing
On the control panel below the Comparison Lamp Supply,
Set the Lamp Stage to 'out'.
Set the Guider to 'field' to acquire the target and align to the slit.
Set the Guider to 'slit' to observe the target.
The following are shortcuts to the observe command. They are advantageous if one wants to do a lot of files in a row of the same nature as they ask for a number of integratrions to be done.
ic> object to start a stellar integration
ic> test to start a test exposure
ic> comps to start Th-Ar exposures
ic>flats to start flat field exposures
ic>zeros to start bias exposures
answer the queries
Another form of shortcut is to type,
- ic> flats 10 180 to get 10 flat integrations of 180 sec each
Image frame will display automatically at the end of the exposure.
If a problem arises during an exposure, after integration starts, use (all in caps)
- ic> A (to abort and discard the exposure)
- ic> C (to resume after the cloud went by)
- ic> P (to pause the exposure)
- ic> R (to stop the exposure early and save it)
- ic> M (to change the exposure time), then a "C" to resume
Night report
In an Oberon window,
% xreport
A night report window will be created. File in the appropriate fields.
Save the xreport periodically.
At end of the night, quit it to file it.
Starting the night
In the coudé slit room:
Remove the cover to the #5 mirror (silver) slit #2.
Remove the cover to the slit.
Verify that the optical elements are in place for cs2.
Verify that the correct slit plug is in place.
For R=60,000 at cs2, use slit #4 8.2x1.2 arcseconds.
The slit plug is removable by lifting the knobbed handle to release the housing.
Pull down the housing using the large black handle.
Unscrew the brass retaining screw.
Remove the plug.
When returning the plug, be sure that the reflective surface of the plug is coplanar
with the reflective surface of the outer mirror.
In the coudé spectrometer room:
Throw the rightmost large switch inside the outer door to open the large mirror cover.
Remove the color balance filters behind the slit.
Remove all 11 optical surface covers on the straight-through path.
Top up the LN2 dewar.
In the electronics room (behind north pier)
Push three buttons:
"HYDRAULIC BEARINGS" green START button to turn on the hydraulics.
There is no discernable change in the button but a faint noise can be heard from the
dome.
"DECLINATION" and "HOUR ANGLE" red ON buttons turn bright.
These turn on the Dec and RA servos.
At the Cassegrain telescope console on the dome floor:
Turn on the console power using the SYSTEM RESET button
Push the dome shutter open button
Push the mirror cover open button
Move the upper windscreen out of the way
Be sure the dome and passage lights are dim or off.
Set up the autoguider
At the TCS console (either on the Cass floor or in the control room)
From the TOOLS menu, enable autodome tracking
From the NEXT menu, choose a target
From the NEXT menu, start telescope tracking
Hold the enable switch until the telescope arrives.
Acquire a bright star
Adjust focus
Test autoguider
Do pointing test and re-zero as needed
Focus the telescope onto the slit
Acquire a bright star.
In the coudé slit room, rotate the mirror to put the light into the alignment telescope on the west side of the optical bench.
Focus the alignment telescope on the slit by loosening the top retaining screw and manually
adjusting the eyepiece all the way out. (One can focus on the field by moving the eyepiece all the way in.)
Focus the star onto the slit using the control handset in the slit room
Nominal focus is near 4800 units.
Ending the night
At the apogee guider:
In File menu, select QUIT
In the TCS window:
From the NEXT menu, select Stow
Select GO NEXT
Go to the Cassegrain console and hold the enable switch until telescope and dome quit.
Tracking will turn off
Telescope will go to HA = 0.0 and DEC=-20 degrees.
Dome will go to West.
In the File menu, select QUIT
At the telescope control console:
Close mirror cover.
Close dome shutter.
Lower upper windscreen enough to cover the telescope.
Hit Emergency Stop to turn off console, RA and Dec servos, and the Hydraulics.
In the coudé slit room:
Cover the #5 mirror.
Cover the slit.
In the coudé spectrometer room:
Cover all optical elements except grating and prism (to avoid moving them).
Top up LN2
At the computer:
Copy data files to Exabyte tape and transfer tar.Z files to home computer.
Logout of Oberon by pulling up a menu in a blank part of the monitor and clicking Quit
Sending tar.Z files to your home computer
It is quick and efficient to send tar.Z files over the Internet to your home computer. However, the process does take some preparation. Within an IRAF window on Oberon, if the files are in .imh, .pix format, do the following
cl> cd /data1/oberon/tgb/<data directory>
cl> !files *.imh > imhlist (to create a file listing all the .imh files in the current directory)
cl> !sed s/imh/fits/g imhlist > fitslist (to change the .imh to .fits on each file name
and store the new list in file fitslist.
cl> unlearn wfits (to get rid of the "yes" or "no" in the "newtape" parameter)
cl> epar wfits
"iraf_file = @imhlist"
"fits_file=@fitslist"
"newtape= (blank)"
cl> wfits (to create a fits file for every IRAF file and retain the same name)
If the files are .fits to start with, begin the process here.
cl> !/opt/local/gnu/bin/tar cvf /data1/oberon/tgb/nite1/nite1.tar nite1/*.fits
(to create a file nite1.tar containing the *.fits files inside a directory /nite1)
cl> !compress nite1.tar (to create a compressed file 'nite1.tar.Z' of the tar file)
cl> !scp nite1.tar tgb@astro:/tgb/tgb/<datadirectory> (to transfer the file to /tgb)
tgb@astro's password: <password>.
nite1.tar.Z (line showing progress of the transfer)
It took <75 minutes to transfer 286 Mb at dinner time.
At home, the tape may be decompressed and extracted,
astro> decompress nite1.tar.Z (to decompress the file)
astro> tar xvf nite1.tar (to extract the *.fits files from the tar file)
The above format for creating the .tar file will lead to the extraction creating a directory /nite1 into which the *.fits files are put.
Writing IRAF files to Exabyte tape
Data may be written on exabyte tapes (2292 Mbyte) in FITS format, ~130 full-sized frames. However, it is inefficient to put that many .fits files on a tape as the time to skip ~100 files is nearly two hours! It is better to put only a few files on each tape.
The IRAF names for the tape drives are listed on a posting just above the rightmost computer monitor. Oberon is connected to mtbc (hi density) and mtac (lo density).
To start the tape dump, in the data reduction window, if the files are in .imh, .pix format,
cl> cd /data1/oberon/tgb/nite1 (to go to data sub-directory)
cl> dir (to verify location and presence of .imh, .pix files)
Load the Exabyte tape in the drive
cl.> allocate mtbc (to assign hi-density drive to Oberon)
cl > dataio - (to launch data I/O package)
da > epar wfits (to verify parameters in write package)
change only the first three parameters as appropriate
"iraf_fil= tgb*.imh" or @filename (a list of files to be copied)
"fits_fil= mtac" (to send the files to tape)
"newtape= yes" or "no"
control-d to escape editor or :go to launch wfits directly
da > wfits (to launch wfits if :go had not been used, do a return for each query)
da > deallocate mtbc (to rewind tape after finished)
Eject the tape
Writing FITS files to Exabyte tape
It is vastly faster to write tar files to Exabyte than to write FITS files directly.
The IRAF names for the tape drives are listed on a posting just above the rightmost computer monitor. Oberon is connected to rst13 (hi density) and rst4 (lo density). Changing rst13 to nrst13 (etc) will cause the tape to rewind after the end of data.
From within an Oberon window,
% tar cvf /dev/rst13 *.fits to write all the FITS files in the current directory to a tar file on the tape.
% mt -f /dev/rst13 status to check on what the tape is doing
% mt -f /dev/rst13 fsf N to skip N files
% tar vf /dev/rst13 > tapelist.txt to list the tape into a file tapelist.txt
% type tapelist.txt to list on the screen the contents of tapelist.txt
At home, the tape may be read using
% tar xvf /dev/rstN where rstN is the local /dev
SUN stuff
Mouse control:
To cut and paste, select text with the left mouse button and paste it at the cursor location with the right one.
Middle mouse button grabs and moves things.
Use the up/down arrows to move to earlier typed lines.
Instrumental Point Spread Function (PSF)
The instrument does spread the light in the dispersion direction (by the echelle) and in the cross-dispersion direction (by the prisms). The shape of one Th-Ar emission lines shows how light is spread.
PSF in cross-dispersion direction:
1. Put the pinhole in the slit (#13). The pinhole is 300 micron in diameter and represents short slit in the cross-dispersion direction.
2. Make an integration of an arc spectrum.
3. Display the frame on ximtool, and type "imexam"
4. Zoom in on an isolated emission line.
5. Place the cursor on this line.
6. Push "e". A graphical window will pop-up and display a contour plot.
7. If the scale of the contour plot is inconvenient then go out of "imexam" by typing "q"
8. In the IRAF window type: epar eimexam and change those parameters which you want to change. Go out of eimexam by typing "Cntrl D"
9. Go into imexam and repeat 3... 9 till you are happy.
PSF in dispersion direction:
10. Put slit #1 in the slit holder. This slit is longer (3.5mm) then the diameter of the pinhole (3.0mm) and therefore less suitable to look at the cross-dispersion PSF. The width (90micron=0.09mm) is however much smaller then the diameter of the pinhole. Therefore this slit is very useful to examine the dispersion PSF.
11. Go through points 2-9