Observing with the Thirty Inch Telescope - Fall 2005

Before you start Observing, check both:  Telescope and Instrument Status   Weather

> tx command        log into thirty@fast.berkeley.edu and communicate with the telescope and instruments
tx help                        print the available commands
tx command help      print the options for any command
Telescope Commands List - check here if you can't find what you need on this page

> tx temps    prints weather information from Leuschner's weather station.  If rain not equal to 0, no observing.

Scripts to start and end observing
> openup           power on, check if slit can be opened, open the slit, keepopen the slit, send dome home, move secondary mirror to 595mils, open primary mirror cover, turn tracking on, set offsets for good pointing.

> tx flip put=12   (Don't forget to set the flip mirror for IRCAM.)  

> closedown      power on, turn tracking off, send telescope home (tx point ha=0 dec=37), close mirror,  close slit, send dome home, rotate flip mirror to face down (tx flip put=102), power off

Telescope Power
> tx power         print the state of telescope power, on or off
> tx power on    turn power on
> tx power off   turn power off

Moving the Telescope
Limits Switches
HA <-55°
HA >+55°
Rules for moving the telescope:
1. Don't point the telescope close to a limit.
2. The software allows you to point to Dec=70°, but the switch will be activated around Dec=63°.
3. The offset command ignores the software limits listed.
4. Turn tracking off when you are close to a HA limit or are not taking images
Note:  HA = LST - RA

> tx point ha=0 dec=37        move the telescope to its home position
> tx point ra=18:36:56.2 dec=38:47:01 epoch=2000      move the telescope with epoch 2000 coordintes

> tx offset dec=-.01        Move the telescope north 0.01 degrees
> tx offset dec=.01 ha=-0.01 cos        Move the telescope north 0.01 degrees and east 0.01 degrees on the sky.

> tx where                    print the current position of the telescope
> tx tel_status              returns values of telescope software limits
> tx abort_telescope    abort a telescope move
> tx move_status         print the move status

Limit Swtiches
If you are getting the message tx power off when you don't want it, you may have hit a telescope limit. Ask for help before you try the following steps.  (1) tx where - to find out which limit is hit, (2)tx power on, (3) tx offset - select the correct direction away from the switch.

> lst                    find the Local Sidereal Time
> bright        see the options for bright command
> bright ra=12:22 dec=33 faint=4 bright=1        find the brightest star, no fainter than 4th mag, no brighter than 1st mag, centered around ra and dec

> bright ra=`lst` dec=30 | dopoint        Point to a bright star near the meridian,  note: the quotes are backward

Tracking starts with the 'openup' script.
Tracking stops with the 'closedown' script.
Tracking does not check the software HA limits and the telescope may hit a switch.  (Bad form!)
Turn tracking off when you are close to a HA limit or are not taking images.

> tx track on     turn on tracking
> tx track off    turn off tracking
> tx track          print the current track rate
If tracking is on, rates should be ha=.004175 dec=0.00000.

Focusing moves the secondary mirror to increase or decrease the distance between the secondary and primary mirror.
The focus indicator reads out in mils (1/1000 of an inch ). Secondary technical details here
> tx move _sec                        Print current location of secondary mirror.
> tx move_sec home               Move the secondary to the home position.
> tx move_sec mils=595         Move the secondary to position 595 mils

The dome does not automatically move when the telescope is tracking.

> tx dome center            Ex:  Center the slit on the telescope's pointing.
> tx dome put=270        move the dome to 270° (slit pointing east)
> tx dome home             move the dome to the home (180°=slit pointing South)

Slit will close after 5 minutes if the 'keepopen' command is not sent

> tx slit                       print the status of the slit (open or closed)
> tx slit open              open the slit
> tx slit keepopen      don't close the slit after 5 minutes
> tx slit closed

If dome is stuck try moving it one way then the other.

Primary Mirror Cover
tx mirror             print the state of the mirror
tx mirror open    open the mirror cover
tx mirror close    close the mirror cover
Flip Mirror
Before taking a picture make sure that the flip mirror is in the proper position.

tx flip put=12    #for ircam
tx flip put=237   #for SETI counter 
tx flip put=328   #for Apogee 47p CCD

If the power has gone off, or the servers restarted recently, the flip
mirror will need to be first homed.

Below is an example script written in C-shell and using image
programs from XVista.
#script to generate a flat by jogging the telescope around
#between exposures then computing the median
#and writing the file 'flat.fts'
set i=0
rm F?.fts       
while ($i<5)
        qimage time=10 outfile=F$i
        tx offset ha=.02 cos
        @ i++
median F?.fts outfile=flat

IR Camera
> tx ccd_status        check the status of the IRCAM.  Ensure: tchip <100K, seq = Fowler

The six position filter wheel has the following filters: > tx filter                           print the filter currently in use
> tx filter help                   print the filter names
> tx filter home                 move the filter wheel to the home position
> tx filter name=H           move the H filter into place
> tx filter name=Kshort  move the Kshort filter into place
> tx filter name=blank      for dark images

Filter Error Messages
If you get an error message indicating a non-integer filter number, the filter is not centered on the entrance aperture. 
To correct: home the filter wheel, then move to desired filter.

More details can be found in the discussion of the rfilter command.
Note: Slot 0 is just clockwise of the home index hole, when looking at the filterwheel as the filters are installed.

Images  Save your images to thirty@fast  ~/group9/

> qimage time=1 outfile=vega.ks.1s.fits        aquire a 1 second image

Copying files to ugastro
When logged into ugastro, copy ~/group9/image.fits from fast the local directory
scp thirty@fast.berkeley.edu:group9/image.fits .

When logged into ugastro, synchronize files on the local directory with those on fast
rsync -e ssh -av thirty@fast.berkley.edu:group9/ .

fast.berkeley.edu =

Leuschner   - Last Update 2005 Sep 26, J. Hare