Starting up

You should get the telescope started and initialized well before it gets dark, to make sure everything is working well. Everything can be initialized without opening the dome.

Power to the telescope

All power to the telescope components is done using software control through several network controllable power strips. These devices allows network control of 24 outlets in the dome, into which various components are plugged in. Power switches in the dome should not be used except in the case of an emergency.

You can control the network power strips using the command line program power1m on|off device; power1m by itself gives the list of device names. You can also control the power using the graphical power program, just click on the item you want to power toggle, and it will ask for a confirmation. As mentioned below, don't power the telescope computer (tocc1m) off without quitting the software first if at all possible!

Starting up the software

Everything for the 1m can be done from inside the control room (or remotely). The telescope is run from the Linux PC, command1m. The normal mode of observing is that a VNC server is run on command1m , and all of the observing programs are run out of this server. If you should need to restart the server, e.g. after a computer reboot, enter vncserver; if you need to kill a running server, e.g. if the window manager fails, enter vncserver -kill :1.

Users on any machine with a VNC client can connect to the server on command1m, and thus control the telescope. On-site, simply enter: vncserver command1m:1. If you are off-site, you must channel the VNC viewer through an SSH channel to be able to access the VNC server: enter ssh -L to open a channeled SSH session, then from another window, enter vncviewer :9.

Ideally, the set of telecope programs will already be running in the VNC window. Under some conditions, however, you may need to know how to restart them.

You can start the suite of telescope control programs by entering

in an xterm window; usually, we use an xterm in the bottom left of the screen. You can create new xterms using the icon on the control bar at the bottom of the display. When you start the telescope control programs, a variety of windows will be opened.

The tcomm script will actually start several different programs:

In the future, the port, ccd, and spec programs may come up in an iconified state, as they are really only necessary for engineering work - you should not need to ever type anything in these windows.

When you start tcomm, the command program should automatically check to see whether various devices (telescope control program, telescope and dome motors, science CCD, and guider CCD) are powered up and responding. If they are, the program will proceed without requesting any input. If not, the program will ask if you wish to power various devices up.

Once the powers are checked, you will be prompted to initialize the telescope and dome if they have not already been initialized - see below for more details on this. After this, there will be question about which port you are observing on (NA1 or NA2), which sets the camera to which commands will be directed (this can be changed later during a command session as well). After the startup questions, you will get a Command: prompt and the program is ready to accept normal commands.

For reasons having to do with the automatic filling of the LN2 dewar for the NA1 camera, the command program should be left running at all times. For completeness, the command to gracefully quit the program is QU.

If there is a commanding problem, i.e. program lost or hung or in infinite waiting loop, you should be able to kill the programs by hitting a CTRL-
in the command window. If any of the other windows fail to disappear with this, they can be killed individually.

!To quit from the program, you enter the QU command. When this is entered, !the program will ask you if you wish to quit the telescope control program !running in the dome. In general, we leave the telescope control program !running. It is very important, however, that you do not kill the power to the !telescope control program in the dome without exiting it gracefully. !Note that the telescope control program which runs in the dome !needs to be exited gracefully !(i.e., commanded to exit) because the program writes out the current !rotator position which is essential to record to prevent cable wrapups. !Because of this, make sure NOT to turn off the computer power via the !network power switch without gracefully exiting the telescope control !software first!

Remote video cameras

There are three webcams in the 1m dome: one located along the ``tube'' of telescope, one looking at the NA1 port, and another mounted on the azimuth disk looking at the inside of the dome in the direction that the telescope is pointing: all three rotate along with the telescope.

All three cameras are controlled by a single program (rvideo, running on ccd1m) that can be started with the start_rvideo command. This opens a video window that shows the image from one camera. You can switch between cameras by clicking on the buttons in the lower right of the video window. Hitting 's' in the video window will take a snapshot, hitting 'u' will toggle update mode (continuous shots) on and off. 'r' redisplays the current image.

You can turn on lights in the dome using the graphical power program (Webcam lights) or on a command line with power1m on lights. Be aware that turning on the lights with the dome or louvers open can impact observations at the 3.5m and/or the 2.5m! The lights are automatically turned off once per hour.

Initializing the telescope

When the computers are powered up, the telescope and CCD programs go through some initialization commands. For the CCDs, no user input is required - you will see a series of commands come up automatically in the CCD control windows. For the telescope, some interaction is required which needs user input either from the command window or from the TOCC computer in the dome. During initialization it is important to watch the rotator to make sure that cables do not wrap - as a result, initialization should either be done in the dome, or, if operating remotely, using a video camera view of the rotator.

After the TOCC computer is booted up, you will see on the screen (both in the dome and in the telescope control window) the following question:

Do you wish to initialize the telescope with a :
I: normal init (uses stored coords to find home positions - will be very
slow if stored coords are wrong)
F: full init - finds home positions without any previous knowledge (but note, telescope must be CCW of azimuth limit, and rotator position must have been previously stored correctly!
M: manual init - prompts for approximate current telescope position, then finds home position via full init. Use if reported rotator position does not match observed position
Q: very quick init (stored coords - assumes telescope hasn't been moved!)
S: skip initialization
Enter your choice:

If the telescope has not been moved by hand, you should be able to do a normal init (I): this will use the saved positions to move to the home switches, and then reinitialize on the home switches. If the telescope has been moved manually, you will need to do a full init (F), which will move the telescope in azimuth clockwise until it hits a limit switch, and in altitude upward until it hits a limits switch, then uses these positions to go back and find the home switches. NOTE, however, that there is no limit switch for the rotator, so if the rotator is lost, doing a full init can lead to cable wrap and DAMAGE, so this must be done with extreme caution, and looking with the remote video at the rotator. If it appears that the cables leading to the rotator are wrapping, hit the emergency stop button (on upper part of left panel in dome), or, if running remotely, by clicking the mouse in the red Emergency Stop section of the power program at the top of the screen. If this happens, you should check with Jon before restarting anything.

You will not be able to move the telescope until it is initialized.

Next the program will ask:

Do you wish to initialize the dome (Y or N)?

Enter Y. The dome will spin around until it finds its home sensor. Very rarely, this fails; if it fails, the countdown on the screen will expire without the home position being found. If it fails, this is not a disaster as you can command a dome initialization from the command prompt later on with the DI command - you will need to remember to do this!

Next the program will ask:

Do you wish to slave the dome (Y or N)?

Enter Y. When the dome is slaved, it should automatically rotate so that the slit is oriented in front of wherever the telescope is pointed.

Finally, it will ask you which camera/Nasmyth port you will be using. This can be changed later with the LEACH/APOGEE and INST commands.

A list of available commands can be viewed at any time using the HP (Help) command.

Weather and telescope safety

You are fully responsible for the safety of the telescope in terms of its exposure to weather. You should not open the dome or the louvers if there is any chance that weather will damage any of the contents in the dome. It is important that you must consider not only clouds and the possibility of rain, but also the humidity and the dust conditions.

Our normal mode of operation is to automatically follow the judgement of the 3.5m telescope. The 3.5m broadcasts its dome status every minute or so. If the 1m receives a "3.5m is closed" message, or if it does not receive a "3.5m is open" message, the dome should automatically close and the telescope should stow. Clearly, it is good to confirm that this actually happens if possible!

It is possible, but highly discouraged to turn off the slaving to the 3.5m dome status; this might be done, for example, to allow the telescope to be moved during the day without continually stowing itself. Slaving is turned off using the -35m command, and can be turned back on using +35m. If you turn slaving off, you will need to enter clear to clear the shutdown flags before you will be able to move, etc.

You can monitor the APO 10-micron all sky image at:
The main APO weather page is at:

Controlling the CCD temperature

NA2 (Leach) camera

The NA2 camera (Leach camera) has a E2V 2048x2048 CCD that is cooled using liquid nitrogen (LN2). Because the dewar has a vacuum to insulate it, it is important that all efforts be made to keep the camera cold continuously; thermally cycling the camera can lead to degradation of the vacuum and contamination on the chip.

The dewar for the science CCD needs to be filled with LN2 to keep the chip cold. We have a remotely operable filling system which can be commanded to fill the dewar. This can be done by simply typing FILL. If the telescope is initialized, The FILL command will move the telescope to the stow position, open the valve from the filling dewar, and then suspend things for the default fill time (currently 6 minutes); you can specify any desired fill time using FILL t, where t is the requested time in minutes. The fill system turns off by timing only; the power to the autofill system is turned off after the requested time. There is NO sensor that actually checks to see if the dewar has actually filled, so if there is some pressure problem, the possibility exists that the dewar will not have been filled. As a result, it is good to monitor the actual temperature.

Note that the valve for the fill system is controlled through the telescope control hardware, so motor power must be on, and the telescope computer running, for the FILL command to actually do anything!!

The current hold time for a full dewar is approximately 13 hours. It takes about 1.5 hours to cool the chip down completely if it starts out at room temperature. In general, it should be possible to fill the dewar just before starting observing and have it stay cold for the entire night.

The normal operating temperature is -125 C; this is controlled by a regulated heater inside the dewar. Sometimes the chip is kept at -130C during the day, just to conserve a bit of LN2.

Apart from manual fills, the CCD software will attempt to do autofills of the dewar when it detects that it has started to warm up. Autofills are triggered when the CCD reaches a temperature warmer than -110 C. If this occurs, the telescope will move to the stow position (if it has been initialized), and do a fill. If the motor power is off when the autofill is triggered (as it should be during the day), the software will automatically turn it on for the duration of the fill, then turn it off afterward; if the motor power is on at the trigger, it will remain on afterwards.

NA1 (Apogee) camera

The NA1 acquisition camera is an APOGEE AP7P with a 512x512 CCD. This is cooled thermoelectrically, and temperature cycling is not so much of an issue.

The thermoelectic cooler can cool the chip to about 50 degrees C below the ambient temperature in the dome. The dark current is a strong function of temperature, so it is desirable to operate as cold as possible. During the summer, you may not be able to get the CCD colder than -30 to -35 C, while during the winter, you might get to -50 or -55 C. If you will be doing dark current subtraction, you will want to get both science and dark frames at the same temperature. Unfortunately since the ambient temperature changes throughout the night, you may not be able to reach the coldest temperatures at the beginning of the night, and you will have to decide whether you want to change the temperature in the middle of your observing.