TV-Guider
The most important commands in overview

Contents

• Login, ....
• Image Grabbing
• Autoguider
• Options in Video-Display Mode
• Some more commands
• Scales and Sizes
• Troubleshooting

Login, start, quit, ...

• login: Login as user tvg. The actual password is given to you by the Calar Alto staff.
• start: Enter tvg at the prompt.
• setup: On startup the program will ask you for the configuration and some other necessary parameters.
• help: Type help or ? to get a short command overview on the Control-Monitor.
• finish: Enter quit in the Command shell to finish the program. Cameras are switched off automatically. If you want to logout completely you have to open the pull-down menue of File in the upper menue bar and select Exit
• Attention: Don't forget to use quit at the end of observation in order to switch off the cameras.
• Attention: Never switch off the PC without successful shutdown procedure !

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Image Grabbing

• grab: grabs images in CCIR TV-mode ( 50 Hz interlaced).
• quick [t_i]: starts a loop, i.e.: integrates t_i (t_i > 0.04 seconds!). seconds and then displays the integrated frame continuously. Just typing quick or clicking on the quick button takes the last value of t_i. At start of the program ti is always set to 1 [sec]. The actual value of t_i is shown in menue Info/Parameter. It also can be changed by set ti value.
• intup: continuously integrates up, displaying every second the actual status. Pressing the Esc-key stops intup. When the count limit of 65536 is reached in distinct pixels (e.g. bright stars) these pixels keep this value, whereas integration continues in the other pixels with lower count values, i.e. sky background and fainter objects.
• Esc-key: or clicking on the Stop-Button generally stops all frame grabbing and guiding activities.
• Overload: In case of Camera-Overload refer to section Overload in the TV-Guider Manual.
• Usage: Use intup for an overview and quick or grab when telescope movement has to be watched.

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  Guiding

  • guide [t_c]: starts the autoguider, using the last centered position (by c, or af, or a previously stopped guide sequence) as reference position. Thus, with guide, the guide object must have been centered before. When using the Find&Guide-Button, the brightest object in the displayed frame is automatically selected as reference star.
    Then, from the very beginning of the autoguider session, the guide star is held on that reference position. Correction of the telescope, - if necessary, - is done after each integration period of t_c [seconds]. The last value of t_c (which is 10 at start of the program) is taken. If you wish to change that value use set tc value or enter the guide t_c command with the appropiate t_c value. The actual value can be read from the menue Info/Parameter.
  • ESC: Pressing the Esc-key or a clicking on the stop-Button stops the Autoguider - as do unexpected actions like moving the telescope by hand, etc.
  • Centering a guide star: Stop the image grabbing (intup, quick, or grab, respectively). Either use af or switch to the Video Display and select a guide star with a Mouse click left. Return to the TV-Control Panel with Mouse click right.

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  Options in Video-Display Mode

  • Entering Video-Display: Click on button Video Display.
  • Leaving Video-Display: Click on right Mouse button or type q.
  • Center an object: Typing c or clicking with the left Mouse button finds the center of moment of an object at/near the current cursor position. The cursor is moved onto this center but the telescope itself is not moved !
  • Orientation: Use o to get the actual orientation (North/East) of the TV-image.
  • Cuts: Cursor keys Up and Down change upper and Left and right change lower limits of image LUT.
  • Zoom: Command z zooms out area around cursor by a factor of 4.
  • Moving the telescope: When in Video-Mode click with the middle Mouse Button. First click defines position 1 (one beep). With the second click at position 2 (two beeps) the telescope moves from position 1 to position 2.
  • Overlay drawing: At the current cursor position you can draw horizontal (h) and vertical (v) lines, markers (k), or circles with different radii ( 0, .. 4). If you want to keep these features through the following image acquisition actions you must disable the Autoclear overlay-function in menue Options/General.

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  Some more commands

  • Flip: Use command flip [x,y,b] to mirror the displayed image.
  • af: (autofind) finds the position of the brightest object in the actual frame and performs a center (c) command. As this may well be an extended object, it is not automatically the best guiding star.

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  Trouble shooting

  • In case of getting stuck in the TV-program (e.g. if there is no way out of the Video-Display for the mouse) you may kill the TVG-program by the following procedure:
    1. Press in one the keys < Ctrl > < Alt > < F1 >
    2. Login as tvg
    3. Enter: ps -ef -grep scosession
    4. Read the given job number jobnr and enter kill -9 jobnr
    5. Type exit, switch to < Ctrl > < Alt > < F2 > again and restart tvg.
  • Reboot Procedure: In emergency case the reboot is done by the following steps:
    1. Press in one the keys < Ctrl > < Alt > < F1 >
    2. Login as tvg
    3. Enter: /tcb/bin/asroot shutdown -g0 -y -i6
  • Shutdown of PC: In order to switch off the computer you first have to do a shutdown.
    1. Press in one the keys < Ctrl > < Alt > < F1 >
    2. Login as tvg
    3. Enter: /tcb/bin/asroot shutdown -g0 -y
    4. Wait until the message
       ** Safe to Power off -- or -- Press Any Key to Reboot **
       appears on the screen.
    5. Now you can switch off the power of the PC
  • In case of power failure the electronic and the PC need some time to recover. If the communication with the TV-electronics fails after startup, the following action may help: switch off for some seconds the TV-electronics at the telescope and wait (some minutes !) for its new initialization.

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    Scales, Field sizes and Mag-limits for a 10 sec Integration

    The Cameras have 764 x 574 Pixel and their scales at the different telescope foci are as following:

    Telescope focus	Pixel per arcsec	Field [arcmin x arcmin]	Limit [mag]
    1.23m Cas	2.5	5 x 3.8	18.5
    2.2m Cas On-axis and Off-axis	4.5	2.8 x 2.1	18.5
    2.2m Cas Slit-view, Optic I	2.7	4.5 x 3.4	19.5
    2.2m Cas Slit-view, Optic II	12.2	1.0 x 0.8
    2.2m Coude
    3.5m Prime K2	2.8	4.5 x 3.4
    3.5m Prime K3	3.5	3.6 x 2.7
    3.5m Cas On-axis and Off-axis, f:10	2.7	4.6 x 3.6
    3.5m Cas On-axis and Off-axis, f:45	12.2	1.0 x 0.8
    3.5 Cas Slit-view, Optic I	2.5	5.0 x 3.8
    3.5 Cas Slit-view, Optic II	4.3	2.9 x 2.2
    3.5m Cas ALFA	2.7	4.6 x 3.6

    We apologize for the missing values, the data will be completed as soon as possible.

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    The TV-Guider Team

    Project:	Uwe Graser	MPIA	graser@mpia-hd.mpg.de
    Software:	Stefan Hippler	MPIA	hippler@mpia-hd.mpg.de
    Electronics:	Ralf Klein	MPIA	klein@mpia-hd.mpg.de
    Maintenance:	Electronic group	Calar Alto	wilhelmi@caha.es
    Support:	Ulrich Thiele	Calar Alto	thiele'at'caha.es

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    Uwe Graser
    graser@mpia-hd.mpg.de