OBSERVING


WEATHER


Conditions for observing

At the start of every night the Observing Assistant at the 4 meter telescope should send out a weather status report. This will show up in any xterm window on the VNC viewer window to Rust or VNC viewer window to Taupe as "Domes are open" or "Domes are closed due to...", etc. This statement is only a guideline - you are ultimately responsible for the decision to open or close due to weather. You can check the weather status at any time by typing "weather" in any xterm window on Taupe, Driftwood, Rust, or Emerald or can be found on the web at http://www-kpno.kpno.noao.edu/weather.shtml. Note that this is not always updated.

There are several criteria that have to be met before the dome may be opened. These criteria have been set with the safety of the equipment and the telescope in mind and are not flexible.

As an added protection measure, whenever the sky is too overcast to observe through, the mirror covers, and preferably the dome, shall be closed.

There are a couple ways to check the humidity and wind speed:


Weather Links


DATA ACQUISITION COMPUTERS

Data acquisition is done on the computer Emerald via the program VNC Viewer for both Mosaic and S2KB. VNC stands for Virtual Network Computing, a software program that allows one to view and manipulate windows on another computer. We use VNC to remotely view the Arcon control computer, Rust (used with Mosaic), and the ICE acquisition computer, Taupe (used with S2KB). For more information on VNC see http://www.realvnc.com.

Emerald has 3 monitors labeled emerald:0.0 (center monitor), emerald:0.1 (left monitor), and emerald:0.2 (right monitor).The right-hand monitor is for image display only, and is not used with S2KB. The computer Emerald is a fast Linux box with a 3.4 GHz (Pentium 4) CPU and 2 Gbytes of memory.

S2KB setup

To begin your observing session with S2KB you should follow these steps.

  1. Log on to Emerald as user 36inch.
  2. On the central console (emerald:0.0) right click on the background to bring up the menu of options. Select Taupe VNC ICE near the bottom of the list. This will open the VNC client in emerald:0.0 in which the window from Taupe will be displayed. Within this Taupe VNC ICE window you will need (i) a Data Acquisition window, (ii) a Data Reduction window, and (iii) an Ximtool. If they are not already up and running, you can bring up these windows from the background menu (right-click) within the Taupe VNC ICE window. Commands for acquiring data will be executed in this Data Acquisition window within the Taupe VNC ICE window.
  3. On the left console (emerald:0.1) right click on the background to bring up the menu of options. Select Taupe VNC GWC at the bottom of the list. This will open the VNC client in emerald:0.1 in which the router (socket server information) is displayed. There should be an xterm window within this Taupe VNC GWC window in which numbers are continuously scrolling by. If not, see the TCS/Instrument Communications section for how to restart this.

Mosaic setup

To begin your observing session with Mosaic you should follow these steps.

  1. Log on to Emerald as user 36inch.
  2. On the left console, right-click on the background to bring up the menu of options. Select VNC to Rust. This will open the VNC client in which the windows for Rust will be displayed. On the center console right-click on the background. Select (Re)start DCA, and Data Reduction to start the Data Capture Agent, its associated GUI and a Data Reduction window. The right console is used exclusively for image display. Either DS9 or Ximtool may be used. Right-click the background to select your image display tool preference. NOTE:The right monitor is only an 8-bit display (to accommodate the current version of X-imtool; a new version with 24-bit color is under development) and should only be used for the display window or there will be problems with the allocation of colors to the display window. We are still working out some undesirable features in this display. If you use DS9 and then want to switch back to Ximtool, you will have to log out of Emerald and then log back in and restart as described above. This will not affect the operation of Rust, but should not be done when you are reading out an exposure or you will lose that exposure.
  3. In the VNC viewer window on Emerald, click in the background of the display and select (Re)START ARCONS. This should bring up all of the MOSAIC GUI's controlled by Rust.
  4. This process takes about 2 minutes and you must also answer one question. A small window labeled "ARCON Console" will appear near the left center of the screen in which various messages will scroll by. After a few seconds a larger window labeled "ARCON Acquisition" will open immediately below this; this is the window you will use for entering all data acquisition commands. A brief greeting message will appear in this window and, eventually, you should be asked

    Do you want to synchronize parameters? (yes)

    When you reply "yes" (or just hit [cr]), the detector parameters loaded into Arcon will match those stored in detpars and the positions of the motors recorded in instrpars will correspond to reality. We currently recommend saying yes at the start of an observing run, but "no" during subsequent restarts. This saves slightly on the start-up time. In either case the IRAF package menus will be printed and the cl> prompt will appear. Some further windows will also pop up at this point. The system is now ready for you to begin observing.

    Occasionally things will get hung up during the process of downloading and initializing the Arcon software. If this happens you may see the message (but probably not)

    ****************************************
    **
    *FAILURE DURING ARCON STARTUP !!!*
    **
    *Use re-start button to try again*
    **
    ****************************************

    In the majority of cases, simply performing the restart procedure will fix this problem, although it may be necessary to try this more than once. If after repeated attempts the system will not start, refer to the Frequently Encountered Problems section of the Mosaic Manual (www.noao.edu/kpno/mosaic/manual) for further advice.

  5. If you end the arcon session at any time the DCA will become disconnected and need to be restarted. Use the Quit button on the DCA GUI to quit the DCA. Bring up a new DCA in the same fashion as on startup. When you start ARCONS on Rust, you can restart the DCA immediately. You do not need to wait until the ARCON start-up has completed.

  6. On an empty desktop on emerald:0.1 or emerald:0.0, right click on the background to bring up the menu of options. Select Taupe VNC GWC at the bottom of the list. This will open the VNC client in which the router (socket server information) is displayed. There should be an xterm window within this Taupe VNC GWC window in which numbers are continuously scrolling by. If not, see the TCS/Instrument Communications section (http://www.noao.edu/0.9m/tcs.html#comm) for how to restart this.

The system is now ready for you to start observing.


HOW TO CHECK AND ZERO TELESCOPE POINTING

How to Check Telescope Pointing

It's best to check your pointing with a bright star at zenith. The first thing to do is load the Bright Star Catalog into the TCS. To do this right click anywhere within the TCS and select the first option "Open Existing Database". This should take you to the file containing all of the coordinate catalogs. The path is
ACE Control System (D:) => ACE => TelescopeControlSystem
The bright star catalog is labeled ACE_BSC5.cat. Select this and click "Open". The catalog will open up into the center of the TCS.

Now find a star near zenith. You can sort the catalog by clicking on the title of any column. Clicking that same column title a second time will sort the catalog in descending order. Scroll down until you find the stars around the current Sidereal Time (this can be found on the right side of the TCS screen, labeled S.T. in purple). Select one that is close to the sidereal time and near a Declination of +32. A 5th magnitude star works best. Once you've selected a star double-click anywhere on that line in the catalog to send the coordinates to the appropriate RA boxes. Confirm the coordinates in the boxes are reasonable and click the "Go To" button.

If Using S2KB:

The best way to discern your pointing with S2KB is to take a very short image (~2 second exposure). Once the image has read out you can fine-tune the pointing if the star doesn't land exactly where you would like it. You can find how far you need to move the telescope from the image. (The pixel scale is 0.6 arcsec/pixel).

If Using Mosaic:

The easiest way to check pointing with Mosaic is to view a bright star on one of the guide cameras. There are two guide cameras at fixed positions (one to the North and one to the South) relative to the CCD field. They are both approximately 2400 arcseconds from the center of the CCD field. Sending the telescope to a specific object will send the object to the center of the CCD field. Using the Offsets tab on the TCS send the telescope (+ or -) 2400 arcseconds in Declination. A positive offset sends the star to the North camera and a negative offset sends it to the South camera. Turn on the appropriate ICCD camera with the ND filter On. Since the offset is not exactly 2400 arcseconds the star will not appear exactly in the center of your screen, but towards the upper right portion of the screen.

If you can not see your star in either of the guide camera fields (and you're sure Mosaic's shutter is not in the "Dark" position) try taking an image of the star on your CCD. Remember to take the offset out (ie reverse the offset) so that the star will land on the CCD field. Then take a short (~2 second) exposure. If you can see the star in the CCD field but couldn't see it in the guide camera field you may need to do some fine tuning to better center the star in your field. Determine how many pixels from the center the star is and use the (0.43arsec/pix) pixel scale to determine how much you need to move the telescope.

How to Zero the Telescope Pointing

If telescope pointing needs to be rezeroed please contact the Site Manager.


CHANGING FILTERS WITH S2KB

There are two filter wheels in the Filter Shutter Assembly associated with S2KB. Each wheel contains 8 slots, giving the capability to house up to 14 filters at any one time. The filter wheels are stacked, meaning both filter wheels are in the light path at all times. For this reason it's important to make sure that at least one of the filter wheels is IN an "empty" position when taking data.

To change filters you need to bring up the Filter Wheel GUI (displayed below):

Move the desired filter into the light path by selecting the radio button to the left of it's name. Do this for both wheels. After selecting a filter in one wheel you should see all the names in that wheel turn gray while the filter wheel moves. Once it has reached the desired position the names will reappear as usual. If the filter names do not reappear black you may need to reinitialize that wheel. To do this, click on the appropriate INIT Wheel # button within the Filter Wheel GUI.

Currently, filters are listed in the headers with numbers as opposed to names. To convert these numbers to their corresponding names you can edit and run the kpfilt script on a specific image (or list of images). The script and instructions for it's use can be found here.


DOME FLATS

Send the telescope and dome to the flat field position by selecting the Dome Flat Park position from the Telescope pulldown menu on the TCS. A box will appear with HA, Dec and Dome azimuth. The correct positions should be HA 3:28, Dec 13:00, Dome az 74. Press "Park" to move the telescope and the dome to the correct positions. It's a good idea to go upstairs and sight along the telescope tube to check the telescope/dome alignment. You may need to bump the dome left or right via the control panel.

The Flat Field lamp control is in the computer room. It is located in the middle of the first electronics rack as you enter the computer room. Control for the High lamps is on the left, and control for the Low lamps is on the right. Each has a toggle switch to turn power on/off and a rheostat to change the voltage to the lamps. To turn on a bank of lights turn the voltage to 0 by turning the rheostat counter-clockwise. Turn the power on with the toggle switch and then turn the voltage to the desired setting. When turning off the lamps be sure to turn the voltage all the way down before turning the power off. Ramping of the lights like this will help preserve the lifetime of the lamps.

Suggested lamp settings and exposure times for each instrument are listed below:

S2KB

Filter ExpTime LampSetting Counts
U 15s High 100% ~30,000
B 13s Low 100% ~30,000
V 5s Low 100% ~30,000
R 3s Low 100% ~25,000
I 3s Low 100% ~25,000
Ha 6580 6s High 50% ~18,000
Ha 6620 6s High 50% ~18,000
Ha 6660 6s High 50% ~18,000
Ha 6700 6s High 50% ~18,000
Ha 6740 6s High 50% ~18,000

Suggested exposure times and lamp settings for MOSAIC are listed below. These exposures should produce images having 5,000-10,000 ADU per pixel to stay within the linear regime (note that each ADU represents ~3 electrons, so there is plenty of signal with these recommendations. To minimize thinking at the telescope, we tried to use the maximum voltage settings when possible (i.e. 100%).

MOSAIC

Filter ExpTime LampSetting
U 10s High 100%
B 18s Low 100%
V 8s Low 100%
R 5s Low 100%
I 6s Low 100%
[OIII] #2
3s
High 100%
[OIII] +29 #2
28s
Low 100%
Halpha
60s
Low 100%
Halpha +4
60s
Low 100%
Halpha +8
60s
Low 100%
Halpha +16/[SII]
60s
Low 100%
SDSS g'
4s
Low 100%
SDSS r'
5s
Low 100%
SDSS i'
6s
Low 100%
SDSS z'
11s
Low 100%
Wash M
3s
Low 100%
DDO 51
18s
Low 100%
White
5s
Low 50%


FOCUSING

Due to the mechanics of the secondary system there is some inherent focus drift (~50 units). To try to eliminate this drift there is a routine that keeps the telescope at the last commanded focus position. If you would like to use this routine, simply check the box beside "Servo" in the Focus GUI. Each time you change the focus the system will automatically keep the focus at this new position. It is highly recommended to keep this box checked.

WARNING: Only click buttons in Focus GUI once and wait until action has taken place!

WARNING: Do not perform other tasks in TCS while changing focus!

WITH MOSAIC:

The best way to focus the telescope is to run a focus sequence "manually". You will be running a focus sequence from the Data Acquisition window but setting the focus on the TCS manually at each step. Focus Inspector GUI

Start a focus sequence and you will be prompted to set the focus each time. Type "observe" and then "focus" in the Data Acquisition window. If you are trying to find focus at the beginning of the night it's best to set the number of exposures taken in the focus sequence to 9. If temperature from night to night has remained constant you can use the previous night's ending focus as your middle focus value. A typical step sizes to use are 50 or 100 units. The smallest focus increment detectable is ~25 units. Once you have entered in all of the information for the focus sequence you will then be prompted to manually set the focus for each exposure in the sequence. To do this you need to bring up the Focus Inspector Gui on the TCS. You can bring this us from the Telescope menu on the main toolbar: Select Telescope => Focus...

You can enter a desired focus into the box beside "Go To Focus" and then hit the "Go To Focus" button. Or you can use the JOG+ or JOG- buttons to jog the focus a specified amount. The current focus is displayed on the toolbar of the Focus GUI, on the main TCS screen near the middle left and at the bottom of the ACE SoftPad.

The range of focus is from 0 to 60000. One step is approximately 0.5 microns. You always want to increment the focus to larger numbers to remove backlash. Nominal focus for both Mosaic and S2KB is around 31000.

Once your focus exposure has read out you can use the mscfocus routine to determine the best focus.

WITH S2KB

When using S2KB it's best to run a focus sequence manually where ICE prompts you to enter the desired focus in the TCS. In the Data Acquisition window type observe and then focus. You will then be prompted for exposure time, starting focus number, etc. If you have a good idea of where focus should be, a good step size to use is 50 units. Otherwise use a step size of 100 units. The smallest step size you will be able to detect is 25 units. You should always move the focus in the positive direction, (ie your focus sequence steps should be +50 units).

Below is a typical focus sequence as seen in the Data Acquisition window.

When the image has read out you can use the kpnofocus routine to determine the best focus. See the IRAF help page on kpnofocus for more information. In your Data Reduction window type kpnofocus. Once you have determined the best focus type it into the Focus Inspector GUI (see above).


GUIDING WITH MOSAIC - THE LINUX GUIDER



Overview

Guide cameras

Mosaic has two fixed guide cameras - one North of the science field and one South of the science field. Guiding is accomplished by selecting a star from one of these fields. Both guide cameras are at fixed positions relative to the science field (~2400 arcseconds North/South). Suitable guide stars are almost always available without moving the telescope from the desired position. The field of view of each camera is approximately 5 arcminutes on a side. It is possible to guide on stars as faint as V~17 near full moon.

Mosaic's guide cameras are intensified fiber-optically coupled CCD cameras (ICCD's), and can be damaged if exposed to bright light, so it is important to protect these cameras from bright stars. The camera controls (shown below) reside on the shelf above the TCS computer, Olive, and are labeled "North" and "South". The video switcher above the controls allows you to switch between cameras. The buttons needed to select the North and South cameras are labeled.


ICCD Camera controls

Video signal is routed from the cameras, through the controls and to the guider computer, Moss. Select the desired camera from the video switcher and adjust the camera from the ICCD Control Panel:

  1. Turn the high-voltage potentiometer completely counterclockwise (10 turn pot)
  2. Toggle the power switch on (on Moss's monitor, pixel defects will appear).
  3. Nuetral density switch should be up (on)
  4. Push the momentary button to enable high voltage (red button).
  5. Slowly turn the high voltage potentiometer clockwise to see if there are any bright stars in the field. If you don't see any stars, turn the potentiameter counter-clockwise, toggle the neutral density switch off (down) and slowly turn the high voltage potentiometer clockwise again, monitoring the video monitor until guider stars appear.

When switching between the two TVs, be sure to turn the high voltage potentiometer fully counterclockwise and turn off high voltage on the TV no longer in use.

Guider software

The computer Moss is the guider control computer. Moss is a dual-boot machine with Windows2000 and Lunix RedHat. When the 2K camera is in use Moss is booted into Windows and the MaximDL software is used to control the guider. When Mosaic is in use Moss is booted into Linux.

By default Moss should boot into Linux. However, if it stops booting and you see lilo: in the upper left hand corner of the screen, type linux. This will boot Moss into Linux and you will eventually get the login prompt. The login and password are on the white board.

You should be at the kpno36> prompt. At this point you'll need to restart the guider software from Emerald. To do this, right-click anywhere on the background on Emerald to bring up the background menu. Select "Restart Guider". This should bring up an xterm window. Eventually this should bring up the video screen on Moss and then the Guider GUI on Emerald. You may see the message "waiting...." repeated many times in this xterm window on Emerald. If so, be patient as it may take a minute or so for the video screen to appear. The Guider Gui on Emerald should appear immediately after the video screen on Moss appears. If not you'll need to bring up an xterm window from the background menu on Emerald and type "xhost moss" (no quotes) in that window. Then select "Restart Guider GUI" from the background menu on Emerald. This should bring up the Guider GUI.

When the guider is running, Moss will show a video picture with two white boxes. The smaller box is the cursor, and the larger box is the guide box. There will also be one or more status lines at the top of the screen containing useful information.

Guider video screen on Moss

The guider video screen on Moss.

Guider GUI on Emerald

The Guider GUI on Emerald.

For more on the Guider Control GUI, see the section "More on the Linux Guider" in the appendix.


Guiding

You will need to make sure the video screen is running on Moss and the Guider Gui is running on Emerald. If not, follow the instructions above under "Guider Software" to start them.

Video signal is routed through the ICCD controller (the grey box above Olive). Make sure the gain on the controller is turned all the way down. Turn on the controller power (left-most toggle switch). Push the red INTEN button on. Make sure the ND filter is on (middle toggle switch). Slowly turn up the gain to ensure there are no bright stars in the field. If you see no stars, turn the gain back down (counter- clockwise), remove the ND filter (toggle switch down) and slowly turn the gain up again, watching for guide stars on the video screen.

There are 2 fixed cameras to choose from - North and South. You can switch between them with the Monitor Input Selector that's just above the ICCD controller.

There are 2 ways to select guide stars.

  1. On the Guider GUI on Emerald, under Guider select "Warp to Star". This should move the large box to the brightest star in the field.
  2. You can also move the cursor on Moss over a star and then left-click to move the guide box over the star.

Now select Guider => Guider On from the Guider GUI on Emerald. You're not guiding yet. You must also turn on the guider on the TCS. On the main screen at the bottom left under "INSTRUMENTS" you'll see "Autoguider". The box to the right of the "Autoguider" displays the status of the guider (On or Off). Click this box to bring up the guider GUI on the TCS. In the Control Status box on this GUI you'll see OFF, ON, N, S. Disregard the N, S buttons as these are only used with S2KB and not with Mosaic. Click the On button. Near the bottom of the TCS autoguider GUI you should see numbers changing in the boxes below "Corrections". If you do not see these numbers changing, you are not guiding. See the troubleshooting section for help.

You will need to turn guiding off in both places (on Olive and Emerald) before moving the telescope. On Olive, click the radio button beside "Off". On Emerald, select Guider => Guider Off from the Guider GUI. Order counts, be sure to turn the guider off via Olive first.

The orientation on the guider video window: North is down and East is to the left.


Hints and Troubleshooting


GUIDING WITH S2KB - the MaximDL software



Overview

In October 2006 new SBIG guide cameras were installed while the original guide cameras were sent out for repair. These SBIG cameras are also controlled through MaximDL and operate the same as the original cameras. The only differences are in connecting to the cameras and switching between the North and South cameras.

The computer Moss is the guider control computer. Moss is a dual-boot machine with Windows2000 and Linux RedHat. When the 2K camera is in use Moss is booted into Windows and the MaximDL software is used to control the guider. Linux is used with Mosaic.

As of January 2003 both North and South guide cameras are fully functional, increasing the likelihood of finding suitable guide stars. See the section below on switching between cameras.

Field of view = 3.3 arcmin x 2.2 arcmin
Offsets:


Setup

To launch the MaximDL software click on the icon on the desktop.

MaximDL icon

When the program is launched you will get a window like this.

MaximDL software

After launching the program select View => CCD Control Window. Click on the Guide tab and then the Settings button. Check to make sure the ControlVia box reads COM1.

Setup Menu Guider Settings

Click on the Setup tab in the CCD control window.

Setup Menu

Make sure the box below Main Camera reads "Fingerlakes" and the box below Autoguider reads "Same as main camera". You can change what's displayed in these areas by clicking the Setup buttons beside each area.

On the same Setup menu now select Connect and wait for the mouse to return to an arrow. Then select Cooler On.



Guiding

Select the Guide tab again and click on Expose.

Guide Menu

A star field should soon appear. The program will pick a suitable guide star and place its coordinates into the Guide Star X and Y boxes. You can select a star manually by entering different coordinates into these boxes, or by double-clicking on the star of your choice.

If you get a message that there are no guide stars available, you will need to try taking a longer exposure or shifting the field slightly. You can change the length of the exposure by using the up and down arrows below Exposure on the Guide Menu. Recommended exposure times are between 3 and 5 seconds. To shift the field you will need to jog the telescope slightly via the ACE SoftPad on the TCS.
If you are having trouble finding suitable guide stars you can use the Guidestar Search program to search for stars nearby.

After the guide star has been chosen, click on Track and then click Start.You are not guiding yet. You need to then turn guiding on via the TCS Autoguider GUI.

TCS Autoguider GUI

Bring up the Autoguider GUI from the main toolbar: Select Instruments => Autoguider. Click On. When the guider is on you should see numbers changing in the boxes below Corrections. Make sure these numbers are changing and that your star is not wandering before starting your exposure.


Focusing

The guide camera focus is controlled via the TCS Autoguider GUI displayed above. The focus range is between 0 and 28000, with typical focus values around 12000 to 14000. The current focus is indicated in the yellow box beside Encoder. To change the focus, enter a desired focus value into the box beneath the current focus setting and click on GO TO.

You can setup the MaximDL software to take continuous exposures of a single star while you change the guider focus on the TCS.
  • Stop guiding.
  • Click on the Focus tab

    Focus menu

  • Make sure there is no check mark to the left of Continuous. If there is, click on that box to deselect it.
  • Click the Reset button.
  • Click Start Focus. This will take a single exposure of the entire field.
  • When the image has fully downloaded you will need to select one of the stars to focus. Drag a box around a star. You should see the numbers in the boxes within the Subframe area changing to the coordinates of the box.
  • Now click on the box beside Continuous to select it. This lets you take continuous exposures of the guide field.
  • You may want to change the exposure time or the time delay between exposures. To adjust these use the arrow keys beneath Seconds and Delay (s).
  • Click Start Focus and change the focus when the status bar reads "Downloading image" until you get a reasonable looking focus.

You can do a rough analysis of your guide star a few different ways:
  • Click on the Inspect tab of the CCD control window to give a surface plot of the star as well as FWHM and Half Flux diameter.

    Inspect Menu
  • From the main toolbar in MaximDL select View => Information Window.
Once you've found a good focus value, click Stop on the Focus Menu and start guiding.

Note: You will need to change the guider focus when changing filters. Some typical guider focus values are given below.

Filter Guider Focus
U 26,000
B 18,000
V 18,000
R 18,000
I 15,000


Switching guide cameras

When changing between guide cameras you need to disconnect the communications to the camera currently in use and reconnect to the other.


GUIDESTAR SEARCH WITH S2KB

If you are having trouble locating guidestars (when using S2KB) you can run a search for guidestars near your field.

To search for guidestars:

Note:The guide cameras are sensitive to V magnitude of 14.5.



THE AUTOMATED CCD LOG

There are two different autologing systems available at the 0.9m. The first is a GUI interface log sheet and recommended for S2KB. The second is an IRAF based log sheet and is recommended for Mosaic.

Both autologs runs on Emerald, and pull information from your image headers to create the log. In order for autolog to run, you must have the TCS/Instrument communications up and running.

To start the S2KB autolog program, on Emerald:

  • cd /md1/autolog
  • Bring up the CCD Autolog Control Panel by typing ccdlog2 &
  • In the "image directory" box, you will need to type in the full path to your working directory of your Data Acquisition window (e.g. /taupe/data1/36inch/night1 or /md1/36inch/night1).
  • Select which instrument you are using.
  • Click on Start Logging. Images will only be written to the log after selecting Start Logging.

The images (.fits images only) are written to the log after the exposure has readout. An example log is show below. Every time an image is logged, the log page is written to a postscript file and saved. These files are stored in the same directory as your images and are called autolog_page1.ps, etc. Each page is then printed when it is full. One nice feature of this log is that you can type virtually anywhere within the log - you can edit any field or add comments wherever you like.

Note:Image root names that contain a period will not show up correctly in the log (e.g. n001.0002.fits). To avoid this, make sure your image root names do not contain periods.

Note:If you use ccdlog2 test images and focus sequences will not show up on the log.

To start the Mosaic autolog program, on Emerald:

For a more extensive description of the Mosaic autolog program click here.


TAPING YOUR DATA

Once you have acquired your data you need to get the data home. Although you can choose to ftp your data home, it is recommended that you have a hard copy of the data by recording it to your favorite media (Exabyte, Dat, DLT, CD, DVD). At the 0.9m you have access to a DDS-2 Dat drive, 3 exabyte drives, a DLT tape drive, a DDS-4 dat drive, as well as CD and DVD-R drives.

Instructions for writing data to DVD can be found at http://www-kpno.kpno.noao.edu/observing/dvd-writing-instructions.html.

The devices in the 0.9m are physically located in the computer room - each labeled with their IRAF and Unix names. Typing devices in an IRAF (Data Reduction) window will produce a list of all the available tape drives with corresponding IRAF and Unix names. Note that most devices are associated with Emerald and are not listed in the devices file. Correct names/id's are located below.

cl> devices

Dome Computer IRAF Name Unix Name Description





36inch emerald mta /dev/nst1 Exabyte Eliant 820


mtb /dev/nst2 DLT


mtc /dev/nst0 DDS-4 Dat
36inch Taupe mta /dev/nrst8 Exabyte 8705


mta8500c /dev/nrst16 8705 - compressed


mtb /dev/nrsx2 Exabyte 8200


mtc /dev/nrst3 Seagate Dat

Taping your MOSAIC data

The steps for recording your Mosaic data to tape via IRAF are identical to those for recording your S2KB data (given below). The only difference is the use of mscwfits as opposed to wfits. Every Mosaic exposure produces 135 Mbytes of raw data, and so, after a good night, an observer may have 100 images, or 13.5 Gbytes of data. Writing this volume of bits consumes a great deal of time and tape, comparable to more than 5 hours and 3 Exabyte 8505 tapes (possibly only 2 tapes if compression is used). We offer a DLT-7000 tape drive at the 0.9-m. The DLT-7000 can write tapes about 3 times faster than the Exabyte 8505 and the tape cartridge holds 7 times the data volume. While tape cartridges cost about $80, they can hold roughly 3 nights of data.  As an alternative, we also offer two Exabyte 8505-compatible (actually, Eliant 820) drives at both telescopes.

You can also write your Mosaic data to tape with the tar command in Unix, but the preferred method is using mscwfits. Whichever method you use, you should read part of your data from tape to make sure it is there.

If you get errors when trying to tape your data, set the blocksize to zero and try again. 

To set the blocksize type:
mt -f /dev/nst* setblk 0

To check the blocksize type:
mt -f /dev/nst* status


**Remember to bring plenty of tapes for the duration of your observing run.

Taping your S2KB data

You can record your data by either using the IRAF wfits task or the Unix tar task

IRAF
In the IRAF Data Reduction window:

Allocate the appropriate drive

Write your data to tape with the wfits task Before leaving with your tape, make sure that all of your data has been written to tape. Rewind your tape (never do this manually!) Deallocate the drive For more help on the wfits task see the ICE manual.

UNIX

In a Unix xterm or xgterm window:

Write your data to tape with the tar task

To list the files on a tape type Rewind the tape with

See the ICE manual for more help on the tar task.


S2KB CCD INFORMATION


WIYN 0.9m / S2KB Frequently Asked Questions



Last updated September 26, 2007