The Danish 1.54-m Telescope DK1.54-m and DFOSC : Set-Up Procedure
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Description

This page contains instructions for mounting the DFOSC onto the Danish 1.54-m telescope, and also for the optical set-up of the DFOSC

• Mounting the DFOSC
• Telescope, DFOSC and Computer Configurations
• Set-Up Procedures
  • Camera Focus
  • Slit Alignment
  • Grism Alignment
  • Set-Up Form
• Checklist

Mounting the DFOSC

• Put the telescope on the west side of the pier.
• Lock the telescope with the `Vela' device.
• Move the rotator to the position where it is possible to insert the DFOSC pin.
• When the pin is in position, tighten all the DFOSC screws.
• Point the CCD dewar towards the south.
• Connect cables as following:
  • A 3-socket power extension coming out from the group of cables covered with a grey protection, has to be fixed close to the right side of the DFOSC controller box. Plug in the following:
    • Power cable for the CCD controller power supply.
    • Power cable for the DFOSC controller box.
    • Power cable for the vacuum gauge.
  • Connect the FASU cable (ELCO connector) to the FASU control unit.
  • Connect optic fibres 1 and 2 to the CCD controller box.
  • Connect the RS232 cable to the DFOSC controller box.
  • Connect the two cables for the sky baffle calibration lamps.
  • store the two spare optic fibres in a safe way.
• Change the moving blocks necessary for DFOSC.
• Set the alpha and delta counterweights to the DFOSC configuration.
• Take out the `Vela' device; this will unlock the telescope.
• Check the telescope balance.
• Switch the cable on the TV monitor in the control room to the DFOSC guiding camera.

Acquisition System and Telescope Configuration

• Telescope Configuration:
  • Cassegrain Mode and Sky Baffle.
  • Dome Control: Automatic.
• Instrument Installation:
  • Before mounting the instrument, take out the instrument cover.
  • Always (both sides of the pier) point the CCD dewar towards to the south.
  • All cables have to be tied up properly.
• Balancing:
  • Set counterweights to values measured during last mounting.
  • Point the CCD dewar to the south (Rotator angle 90 degrees with telescope east of pier, and -90 degrees west of pier).
• DAQ System:
  • BIAS (Brorfelde Image Acquisition System) is running on a Linux PC 150 MHz Pentium, with 40 MByte RAM, and 2 hard-disks (1.3 GByte IDE and 2.1 GByte Conner SCSI). IP address of pc2_1d5: 134.171.143.21
    • Username: dfosc, password: (ask)
  • W/S HP-735 Dual Screen is used to run the DAISY program and work with MIDAS. IP address of ins1d5: 134.171.123.4.
    • Username: daisy, password: (ask)
  • DAT tape unit HP6400 /dev/rmt/0mn

Set-Up Procedures

The 2p2 Team operations is responsible for the set-up of DFOSC. To set up DFOSC it is necessary to: (1) insert the required optical components; (2) focus the camera; (3) align any slits and grisms which have been requested; and (4) fill in the optical set-up form.

• Camera Focus
• Slit Alignment
• Grisms Alignment
• Optical Set-Up Form

Focusing the Camera

The Hartmann Test is used to focus the camera. Turn the flat field lamp on, or slightly open the dome door. With only the sky baffle cover open, you get enough light. The procedure to follow is:

• At the ins1d5 WS using DAISY set:
  • Aperture Wheel: Pinhole Plate
  • Filter Wheel: Free
  • Grism Wheel: Hartmann 1
  • Camera Focus: Any value between 2300 - 2400
  • CCD window:
    • X= 900 - 1200
    • Y= Full Range
  • Exposure Time: 2 sec.
• After you take the first exposure with Hartmann 1, change to Hartmann 2 and take another exposure.
• On ins1d5, run the MIDAS batch `@@ ff Hartmann1 Hartmann2'. The batch gives you:
  • Focus Shift: pixels
  • Focus Spread: pixels
  • Focus Accuracy: % of spread (must be lower than 25% of spread)
• Move camera focus accordingly: 0.10 pixels corresponds to 20 encoder units.

Slit Alignment

Spectroscopic slits have to be aligned along CCD rows. Turn the flat field lamp on, or slightly open the dome door. With only the sky baffle cover open, you get enough light. The procedure to follow is:

• At the ins1d5 WS using DAISY set:
  • Aperture Wheel: Slit you need to align.
  • Filter Wheel: Free
  • Grism Wheel: Free
  • CCD window:
    • X= Full Range
    • Y= 900 - 1200
  • Exposure Time: 1 sec
• After the image has arrived at the WS, use MIDAS and type `create/gui set-up' to get the set-up graphic user interface.
• In the `SETUP GUI' select the option `ALIGN', and choose `2 points'. Follow the instructions provided by the batch.
• The batch gives:
  • Slope: degrees
  • Misalignment: pixels/1000 pixels (must be smaller than 0.3 pixels)
  • Position: "Y" position on the CCD
  • Offset correction in encoder units.
• If you have to do a correction, go to the `CCD Window' in DAISY and do the following:
  • Go to the `MAINTENANCE' option.
  • Click on `Enable NEXT options'.
  • You will asked if you are authorized staff, click OK.
  • Go to the `MAINTENANCE' option again.
  • Click on the `Center Wheel' option, and a window with the different offset positions for the slit, filter and grism wheels will appear.
  • Apply the offset correction in the slit column.
• Repeat the above procedure until the slit is aligned.

Grism Alignment

The grism is aligned such that the dispersion direction is along the CCD columns. Turn on the FF lamp and open the main mirror cover. The procedure to follow is:

• At the ins1d5 WS using DAISY set:
  • Aperture Wheel: Pinhole
  • Filter Wheel: Free
  • Grism Wheel: Grism you need to align.
  • CCD window:
    • X= 900 - 1200
    • Y= Full Range
  • Exposure Time: 10-20 sec
• After the image has arrived at the WS, select `ALIGN' in the set-up GUI, and choose `2 points'. The batch will provide instructions to be followed. The batch gives:
  • Slope: degrees
  • Misalignment: pixels/1000 pixels (must be smaller than 0.3 pixels)
  • Position: "X" position on the CCD
  • Offset correction in encoder units.
• If you have to make a correction, go to `CCD Window' and do the following:
  • Go to `MAINTENANCE' option.
  • Click on `Center Wheel' option.
  • Apply the offset correction in the Grisms column.
• Repeat the above procedure until the grism is aligned.

Updating the Optical Setup Form

The Optical Setup Form is updated for the new set-up by:

• Click on `MAINTENANCE' option in the `CCD Window' menu in DAISY.
• Click on `DFOSC Setup'. A window appears, update the information in this window.
• Click on `FASU Setup'. A window appears, update the information in this window.
• To obtain a hardcopy, do a `PRINT'.

Send comments to <ls-220@eso.org> Last update: Nov 11, 2002