Observing with the Thirty Inch Telescope -
Before you start Observing, check both: Telescope and Instrument Status Weather
> tx command
log into firstname.lastname@example.org and communicate
with the telescope and instruments
print the available
tx command help
print the options for any command
Commands List - check here if you can't find what you need on this
> tx temps prints weather information from Leuschner's
weather station. If rain not equal to 0, no observing.
to start and end observing
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
> 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),
> 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
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
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
> tx tel_status
returns values of telescope software limits
> tx abort_telescope abort a telescope move
> tx move_status print the move
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.
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
> 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
> tx move _sec
location of secondary mirror.
- The home position is at 0 mils
- Typical IR camera focus is 595 mils
- Maximum travel is 1360 mils
- Values outside of 0 - 1360 indicate errors. To correct:
tx move_sec home
- Around 80 seconds is required to move the secondary from home to
- There is backlash with the mechanism.
> 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
> 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
print the state of the mirror
tx mirror open open the mirror cover
tx mirror close close the mirror cover
Before taking a picture make sure that the flip mirror is in the proper
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'
qimage time=10 outfile=F$i
tx offset ha=.02 cos
median F?.fts outfile=flat
> 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
the filter currently in use
- slot=3=open (no filter)
- slot=4=blank (aluminum plug)
> 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
scp email@example.com:group9/image.fits .
When logged into ugastro, synchronize files on the local directory with
those on fast
rsync -e ssh -av firstname.lastname@example.org:group9/ .
fast.berkeley.edu = 184.108.40.206
- Last Update 2005 Sep 26, J. Hare