SPUPNIC

SpUpNIC User Manual

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Introduction

This is the user manual for the newly upgraded spectrograph at the Cassegrain focus of the 1.9 metre telescope. Most of the mechanical components have been rebuilt, the optics have been significantly improved, and the instrument has a new detector. We hope you enjoy using it!

The instrument has two subsystems, the PLC subsystem (controlling the things that move) and the detector subsystem (controlling the data acquisition).

The instrument software has been built using the new SAAO software framework. The drivers for the detector and PLC subsystems now run as stand-alone processes, and the user interface runs as a separate process on top of these.

Usually, users will connect to the graphical user interface, but certain diagnostic functions can only be accesses using the command line interfaces. These are all described below.

SpUpNIC User Interfaces

SpUpNIC's control displays are labelled "Monitor 1" and "Monitor 2", and are located to the right of the TCS monitor in the warm room. To launch the SpUpNIC Control GUI, click on the rainbow icon in the menu bar on the left-hand-side of Monitor 1. All of the spectrograph subsystems (e.g. grating angle, slit width, arcs, exposures, guide mirror) are controlled from this GUI.

There is an accompanying SpUpNIC Quick Look GUI, which displays each spectrum after readout. To launch the SpUpNIC Quick Look, click on the black absorption line icon below the rainbow icon.

Start of run

In the SpUpNIC Control GUI:

• At the start of your run, click on the "Advanced" tab. In the "Observer Info" box, enter your name and run number. You can determine your run number from the triplicate "CCD and Unit Spectrograph" log book, stored in the "Log Books" section of the bookcase, on top of the chest of drawers beside the door to the observing floor (behind you, if you're sitting at the SpUpNIC interface). Your run number will be one greater than the previous observer's run number, listed in the log book.

Setting up the Grating

• If a grating is mounted in the spectrograph, it will be indicated toward the bottom of the "Instrument Setup" section, e.g. "gr8" in the Grating field indicates that grating 8 is mounted. Below this is the grating angle field. If you need to mount a different grating, rotate the grating to 0 degrees by entering 0 in the "Grating angle" box and pressing "Go". You can also move the grating by entering the number of degrees you wish to move it by in the "Grating angle increment" box below.

• Once you have the correct grating in the spectrograph, you can determine the desired grating angle from ....., enter this in the "Grating angle" box and click "Go".

• Any required order blocking filters for your grating setting are listed .....: select them from the dropdown menu below the grating angle control.

Automated grating angle determination.....

Arc lamp and filter selection

• Two arc lamps are permanently mounted in the spectrograph - you no longer need to swap out a lamp - but the arc lamp filters are still changed manually. On the spectrograph, the CuAr lamp is in the vertical housing, with two slots for filters below. The CuNe lamp is below it, housed horizontally, similarly with slots for two filters in the light path. Filter requirements are listed in .... and the filters are stored in a small, labelled wooden box on the bench in the grating room (North-West corner of the dome).

• The arc lamps are controlled from the "Lamp/Mirror Settings" section of the SpUpNIC Control GUI: Arc 1 is CuNe, Arc 2 is CuAr. Click the appropriate "Change" state button to switch the desired lamp on/off, and to move the arc mirror into the beam to take and arc exposure, and out again when finished.

Focusing the spectrograph

Before each night's observations, you should focus the spectrograph. This is done using a scripted Hartmann test, which moves a shutter halfway into the beam, takes an arc exposure; then blocks the other half of the beam and takes a second arc exposure. The arc lines are then cross-correlated to measure the shift between the two. The procedure is repeated at a range of camera focus positions until the line shifts are minimised, indicating best focus. This procedure can be performed manually or automatically. For an auto focus run:

1. Above the grating setup, select slit width 7: 1.05" (or smaller) from the dropdown meny and click "Go".
2. In the "Exposure/CCD info" "Advanced" subtab, select CCD modes "Faint" and "Slow" from the dropdown menus, and CCD Binning "1x2".
3. In the "Exposure/CCD info" "Main" subtab, select "Exposure type" = ARC from the dropdown menu, and enter e.g. ..... seconds in the "Exposure time" box.
4. Move the arc mirror into the beam and switch on the appropriate arc lamp for your grating setup.
5. In the "Instrument Setup" section of the SpUpNIC GUI, select the "Auto" tab.
6. Enter an "initial focus position" (e.g. .....), a "focus increment" (.... is recommended) and a number of "steps" (try .... iterations) and click "Run". As the procedure runs, you will see the current "Camera focus" field changing, Hartmann shutters indicate "Moving", ...
7. On completion, in the SpUpNIC Quick Look GUI, in the log box to the left of the spectrum display window, you will see a list of focus positions and their corresponding pixel shifts. Best focus corresponds to a shift of zero.
8. Enter the best focus into the "requested" Camera focus box on SpUpNIC Control's "Instrument Setup" window and click "Go".
9. Switch off the arc lamp and move the arc mirror out of the beam.
10. Does Hartmann test end with shutters out of beam......?

The Graphical view Normal operations are performed in the "Main View" tab of the SpUpNIC Control interface. On the right-hand-side is a graphical representation of the instrument, which shows the light path through the various components controlled by the GUI. You can click on the guide mirror, arc mirror, rear of slit mirror and Hartmann shutters to move them in and out of the beam, and on the arc lamps and slit illumination to switch them on and off. A blue border surrounding the graphic indicates that the spectrograph is in "Acquisition" mode, i.e. some component is in the beam that would obstruct its path to the science detector.

Observing setup

• Target name and coordinates can be entered into the "Target Info" box..... can they ? How? Where do you save a catalogue to and in what format?

Focusing the acquisition camera

1. With the guide mirror out of the beam (either set the "Science" state in the "Lamp/Mirror Settings" section of the SpUpNic control GUI -- if it says Guide Mirror "Acquisition", click "Change" -- or click on the guide mirror in the graphical view to allow the beam through the hole in the guide mirror.
2. Turn on the slit illumination (in "Instrument Setup" move the Slit illumination slider to .... and click "Change" to turn on the lamp).

On the TCS:

1. Start exposures with the acquisition camera and tune the exposure time/LUT sliders/slit illumination to allow good contrast of the scratches on the lower slit jaw.
2. Adjust the acquisition camera focus in the bottom right "Camera Focus" box until the scratches on the slit jaw appear as sharp as you can get them.

Recipe for setting up slit position on the TCS - using SpUpNIC Control GUI

The purpose of this step is to figure out where on the acquisition image you need to place your star, in order for it to land pretty close to the ideal spot on the slit. Very bright stars can be seen reflected on the slit jaws, and can be placed on the slit directly, but this is not the case for fainter stars, which need the superior reflectivity of the guide mirror in order to be seen on the acquisition camera.

1. Move the guide mirror into the beam, either by setting the "Acquisition" state in the "Lamp/Mirror Settings" section of the SpUpNic control GUI (if it says Guide Mirror "Science", click "Change"), or by clicking on the guide mirror in the graphical view.
2. Acquire a bright star (e.g. ~4 mag from the Bright Stars chapter of the Sutherland Almanac, available in the warm room), roughly centre it on the acquisition camera and continue exposing.
3. Move the guide mirror out of the beam.
4. Move the rear-of-slit mirror into the beam ("Lamp/Mirror Settings" section, "RoS mirror" change from "Out of beam" to "In beam").
5. Turn on the slit illumination (in "Instrument Setup" move the Slit illumination slider to .... and click "Change" to turn on the lamp). Tune the exposure time/LUT sliders on the TCS until you can clearly see the slit running horizontally across the acquisition image, approximately halfway up.
6. Using the hand paddle, move the telescope to place the star on the slit, approximately one third of the image width away from the right-hand edge.
7. Turn off slit illumination.
8. Open a terminal on Monitor 1, and run the following commands

 * ssh -Y tcs@tcstest
 * password Saaotcs
 * sudo ./1X1_thread_forms
 * password Saaotcs

1. .....description of pottercam when functioning sensibly.......
2. An image window for the rear-of-slit camera will pop up. This looks up at the slit from behind, to enable you to check that your star is centred on the slit. Move the telescope such that the star falls on the centre of the slit image in both x and y.
3. Move the rear of slit mirror out of the beam and take a test spectrum (e.g. 20 seconds) of the bright star (in "Exposure/CCD info" pane, select "Exposure type" "Science" from the dropdown menu, enter "20" in "Exposure time" and click "Expose").
4. The resulting image will be displayed on Monitor 2. You are aiming for the spectrum to fall on approximately the central row of pixels. If the spectrum is too high, move the telescope slightly ...east?west?  ; if too low, move the telescope slightly west/east.....? ?
5. When you are happy with the position of spectrum on the image, on the TCS, add a red marker over the position of the star on the slit (TCS "Pointer" pane: "Markers", "Add a red marker").
6. Finally, move the guide mirror into the beam, and add a second red marker at the position of the star. This marker will be used to approximately position stars on the slit that are too faint to be seen reflected off the slit jaws.

Focusing the telescope

1. Acquire a ..... mag star with the guide mirror in the beam

Quick Start

This is an overview of taking data; if you're unsure about anything, the Advanced User Guide has much more information.

• If the main user interface and quick-look interfaces are not running, they may be started from the panel on the left edge of the screen. The main user interface is started with the icon of an absorption spectrum, and the quick-look interface from the icon of an emission spectrum.

• Fill in target information (optional).

• Set the focus required (or use the Hartman routine; see the Advanced User Guide).

• Set the slit width.

• Ensure that the grating you require is inserted, and set the grating angle.

• Select the required filter (or leave the filter open).

• Select the acquisition type (ARC, BIAS, SCIENCE, FLAT, TEST)

• If appropriate, set the exposure time and number of exposures.

• If taking a science image, acquire the target, and ensure that it is visible through the slit.

• If taking an arc, ensure that the arc mirror is in-beam, and the chosen arc lamp is on (remember to turn off the arc lamp and move the arc mirror out of beam when done).

• Start the acquisition with the Expose button

• The countdown timer will show the time remaining, and the progress bar will first show the exposure completion state, and then the readout state.

Advanced Users Guide

• The main user interface has a number of tabs:
  • The main tab, in which you'll spend most of your time,
  • The Advanced tab, which may be used if things go wrong,
  • The engineering tab, which displays various diagnostic settings
  • The other tab

• There is also a panel on the right, showing a schematic of the optical components.