OBSERVING INSTRUCTIONS FOR MzLS

Still need to incorporate the following instructions:

• Pointing the telescope, and re-zeroing the pointing using the numbers reported by MOSSTAT
• Focusing the camera
• Running the guiding loop (or choosing not to)
• Instructions for converting the JSON files into the ones that the telescope can read (what are these called?)
• Instructions for checking in the updated tile file (probably also need to add this to the DECam observing instructions)
• Coverage plots, which we've not yet ported from the DECam version

These are instructions for observing for MzLS.

Read the Manual for MOSAIC operations

To see the Mosaic1.1 manual, go here: ​http://www.noao.edu/kpno/mosaic/manual. Mosaic3 also runs NOCS. We'll hopefully have an updated manual soon.

Some Preliminaries

Observing can only be done from the Mayall control room or from within the KPNO/NOAO network using a VPN.

Log on to the mayall-2 computer to operate MOSAIC3:

Username : observer
Password : If you have to ask, you'll never know. If you know, you need only ask.

To run MOSAIC3, you just need to use the MOSAIC3 Menu GUI. But you can also log into the mosaic3 computer from mayall-2:

ssh -XY observer mosaic3

and use command line nocs commands.

To run the python nightlystrategy scripts and IDL, log on to the mzls account on the mayall-idl.kpno.noao.edu machine:

Username : mzls
Password : Ask Arjun, David, or previous observers

These environment variables define the locations of data and code:

$HOME=/home/mzls
$MOS3_DATA= -- This is where our raw data files are written. Should be something like /mosaic3/data2/observer/20160202. This is a network mounted disk on the machine mosaic3.
$MOS3_OBS=$HOME/products/mosaic3 -- This contains the observing product with code and versioned log files.
$PS1CAT_DIR=$HOME/ps1/chunks-qz-star-v2 -- Pan-STARRS1 catalogs used by the IDL DECSTAT routine for computing astrometric offsets and photometry

These path names are set in the .bashrc file, or can be set for example with "export MOS3_DATA=/mosaic3/data2/observer". The $MOS3_DATA directory must be updated to point to the current night's data.

Other directories in the home directory are:

data/ -- Link to the top-level data directory, where each night is stored in subdirectories like "20151213"
exec/ -- Cross-mount to mosaic.kpno.noao.edu:/home/observer/exec
products/ -- Code checked out from the SDSS and the DESI svn repositories

Documentation for the IDL scripts can be printed from the IDL prompt with the DOC_LIBRARY command, for example:

      IDL> doc_library,'mosstat'

Date convention

All dates in log files are set to the local date of the beginning of the night. For example, any data taken during the night of December 13/14, 2015 will be written as 2015-12-13. This is consistent with how the NOAO Science Archive timestamps and saves the raw data files.

Are we there yet?

For reference, the tiles we’d be observing with MOSAIC3 in z-band are:

  IN_DESI = 1
  DEC > 30
  88 < RA < 301
  PASS <= 3

That’s 48760 tiles. If instead we limit to DEC > +34, we have 43,230 tiles.

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EXAMPLE RUN THROUGH FOR A GIVEN NIGHT

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[1] Update everything

Log into the mzls account on the mayall-idl machine.

Update the code, log files and most importantly the tile file:

cd ~/products/mosaic3
svn up
cd ~/products/observing
svn up

[2] Set the paths

The data path must be changed to point to the current night's data. Edit the entry for MOS3_DATA ~/.bashrc file, for example if the start of the night is 13 Dec 2015 change this to

export MOS3_DATA=/mosaic3/data2/observer/20151213

[3] Create nightly plan

Detailed instructions for NightlyStrategy?

Create the nightly plan from the available tiles. This will read the tile file to see which ones are already completed.

cd ~/products/mosaic3/json
python py/mosaicstrategy.py -t obstatus/mosaic-tiles_obstatus.fits -d *UT date at ''start'' of night* -p *portion of night* -pass *pass number*
python ./py/jnox.py --in *JSON input file --out *Output shell script
scp *output shell script to the /home/observer/exec area on mosaic3

[4] Start up mosaic control software

On mayall-2, double click on the MOSAIC3 icon, which brings up the MOSAIC3 Menu on the left edge of the screen.

1. Start the camera control program by pressing the yellow "Start Cameras" button. Wait for this to finish, then dismiss the screen by typing any key as instructed
2. Start the MOSAIC3 NOCS software by pressing the blue "Start MOSAIC" button. This launches a blue xterm. Move it out of the way and watch all the windows come up
3. Rearrange the desktop as needed.

If, for some reason, the buttons do not work, you can start up the software on a command line as follows: On mayall-2 open a terminal window and:

ssh -XY observer@mosaic3
nocs start ccp (this is equivalent to the "Start Cameras" button on the MOSAIC3 Menu)
nocs start all (this is equivalent to the "Start MOSAIC" button on the MOSAIC3 Menu)

Once nocs is up and running, rearrange windows as desired, and check the status of the system by typing the following in a nocs terminal window:

nocs status all
nocs fullstatus ccp

4. Launch CCD temperature monitor from "MOSAIC Temps" icon (CCD and Dewar temps should be around 173C and 90C respectively)
5. Launch TCS acorn monitor from "VDU" icon
6. 4MAPS monitor from "4MAPS" icon
7. Launch Truss temperature monitor from "Truss C" icon

All these icons are on the right side of the left hand screen of the mayall-2 computer display. Rearrange the busy desktop as needed ...

[5] Set the PROP-ID and Project Info

On the NGUI window, press the "Set Project" button and fill out the relevant information. For example,

Principal Investigator: Arjun Dey
PIs Email Address: dey@noao.edu
Actual Observers: Tristram Shandy, Bertram Wooster
Observing Assistant: Karen Butler
OA's Email Address: 4meter@noao.edu
Proposal Identifier: 2016A-0453
Telescope System: KPNO Mayall 4m
Science Instrument: Mosaic 3

Please ensure the Proposal Identifier number is correct''

Then, in one of the NOCS xterm windows, type: "nocs set project"

[6] Take a test image to ensure system is working

Check that all is well by taking a test zero exposure. On the IRAF window, check the image statistics by cd-ing to the correct directory and typing "mscstat <filename>" All rms values should be about 4-6 adu/pix; the exception is amplifier [6] which has an rms~8-10adu/pix. If any one amplifier shows very high noise, then execute the following commands in a nocs window:

nocs reset ccp
nocs init ccp

Then take two more zeros; the first one will be junk, but the second one should be OK.

[7] Take dome flats and zeros

During the afternoon (after 4pm), take dome flats with the telescope pointed at the white spot.

1. Check that telescope is pointed to the white spot with mirror cover open
   
2. Take 10 zero exposures
   
3. Turn on low dome flat field lamps at 100% intensity (~50V)
   
4. Create a dome flat script using the NGUI interface. Exposure times as follows:
   

z-band : 20 sec
r-band : 25 sec
g-band : 20 sec

Take 11 flats in z-band every night; only take flats in other bands if you intend to use them. Counts should be ~18-20k adu.

5. Take 20 zero exposures
   
6. Go eat dinner
   

[8] Just before observing

1. Start the automated script for updating the tile file

The FITS file listing which tiles have been completed should be updated throughout the night. This file is $MOS3_OBS/obstatus/mosaic-tiles_obstatus.fits. The following IDL command will monitor exposures as they are taken throughout the night, automatically updating this file. From a terminal on the mayall-idl compute, in the mzls account, start this running:

idl
   muptiles

At the end of the night, you should check the updated tile file into the svn repository.

2. Start the automated script for monitoring the data quality

From another terminal in the mzls account, start this running:

idl
   mosstat_continuous

This will run mosstat on each frame as it shows up and display the results on the screen.

[9] Observe - start of night

No on-sky observations are permitted before 12 deg twilight.

0. Take a zero image to ensure everything is working
1. At start of night, check telescope pointing and zero the telescope coordinates using a bright star placed on the telescope boresight (defined as the center of the mosaic3 focal plane).
2. Move to the beginning of the first MzLS tile position
3. Focus the telescope
   

- create a focus script using the NGUI
 - run the focus script from the /home/observer/exec directory 
 - analyze the focus image using mscstarfocus 
    - edit the mscfoc.cl script to correct the name of the image that needs to be analyzed 
    - mark about 10 stars around the image; mark the top star in each sequence using "m"; "q" to quit 
 - log the Truss temperature 
 - set the telescope focus  
 - focus the guiders; this way you can use the guider images to monitor focus drifts

Example of a focus sequence

Observe - all night long!

Execute mzls*sh script

In a nocs terminal window (on the mosaic3 computer): Go to /home/observer/exec, and execute the mzls*.sh script.

Monitor focus by checking the image quality on each frame. Keep track of the truss temperature variation and modify the focus as needed. The Mayall has astigmatism, so one can tell from the shape of the images which way to move the focus.

Example of a focus sequence

If conditions change compared to assumptions for the script, re-run strategy.

Keep an eye on the CCD and dewar temps (should be around 173C and 90C respectively)

If you have problems ... =

See MayallZbandLegacy/NotesforObservers/Problems

Checking the Sky Brightness, Seeing and Transparency

The observing strategy files take as input these environmental conditions for setting the exposure times to achieve the required MzLS survey depth.

From an IDL prompt, use the MOSSTAT routine to analyze the latest image on disk:

   IDL> mosstat

There are keyword options that allow you to choose different exposure numbers or CCDs within that exposure. For example, to analyze chip 'im16' of the exposure number 12345, type:

   IDL> mosstat, 12345, ext='im16'

The full documentation can be seen with:

   IDL> doc_library,'mosstat'

To just have mosstat run continuously whenever each image appears, use

   IDL> mosstat_continuous

Correcting the pointing

Keep an eye on the mosstat output. If the telescope pointing has gone off by more than about 30 arcsec (which happens!), then this routine will likely fail to match stars. If this happens, the operator will need to recenter the telescope. One can do this by telling the OA to offset the telescope in the *OPPOSITE* direction of the computed mosstat positional offsets, i.e., if you see:

RA, Dec offsets: -15.230 14.756

ask the OA to offset the telescope +15" in RA (i.e., east) and -15" in DEC (i.e., south) and zero the coordinates there. Only apply these offsets when the exposure is done (i.e., during readout) and when the telescope is not moving!

One can also check the observing progress using the almanac command:

IDL> almanac, 10001, /noprint

will print out a summary of all the frames from 10001 to the present in a nice tabular form (widen the window). This is useful for checking how the seeing and sky brightness have varied since frame 10001, and whether one should create and upload a new JSON observing script. The /noprint just prevents the decstat output for every frame; if you want to see that, then don't use the /noprint keyword.

Please write useful human logs

Keep a log about weather conditions, which pass you observed, and telescope problems. Follow the example on the pages at MayallZbandLegacy/ObservingLogs .

Catastrophically bad frames (such as saturated frames, or where the telescope moved) are recorded and svn-checked-in to ~/products/mosaic3/logs/bad_expid.txt .

In case of technical difficulties

We have in the past encountered technical difficulties that have restricted where we can observe to a specific range in RA/Dec.

If this happens during your run, you have several options:

1. First, try running mosaicstrategy.py with an appropriate --airmass-limit and/or --moon-sep-limit to try to keep to the required range of tiles.
   
2. Shorten your observing period (using --start-date,--start-time and --end-date,--end-time) such that it's scheduling fewer tiles.
3. Increase the assumed seeing such that it schedules longer exposures.

[10] End of night

No on-sky observations are permitted with MOSAIC3 before 10 deg twilight or after 10 deg dawn. No twilight flats are allowed.

Shut down the software

1. Ensure that the "Shutter" and "ready" are both in the "Dark" position on the MCCD gui
2. Press the red "Stop MOSAIC" button on the MOSAIC Menu GUI. Wait for this to finish.
3. Then press the yellow "Stop Cameras" button on the MOSAIC Menu GUI.

If the buttons do now work, then go to one of the NOCS xterm windows and type:

     nocs stop all (equivalent to pressing the "Stop MOSAIC" button)

Once nocs is shut down, type

     nocs stop ccp (equivalent to pressing the "Stop Cameras" button)

Once this is done, type

     nocs status all
     nocs fullstatus ccp

and make sure everything is shut down. Only when this is done, is it safe for the OAs to put on the lights in the dome.

Check in the updated tile file

At the end of the night, you should check the updated tile file into the svn repository. On the mayall-idl computer:

   cd $MOS3_OBS/obstatus
   svn commit obstatus/mosaic-tiles_obstatus.fits --username <YOUR-NAME>

Create the Almanac and Almanac plot files

At the end of the night, create the Almanac files and check them into svn.

- cd products/mosaic3/logs
- idl
- almanac,<first exp num>
- plotalmanac,'Almanac_date.fits',ps='plot_Almanac_date'
- exit
- svn add *Almanac_date*
- svn commit *Almanac*

For example, for the night of March 26/27, 2015, this is done with:

cd products/mosaic3/logs
idl
   almanac, 424978, 425143
   exit
svn add Almanac_2015-03-26.*
svn commit Almanac_2015-03-26.*

There are actually two versions of this file, one that is an ASCII file (with .txt extension) and one that is a FITS file (with .fits extension).

Create a log file

THE FOLLOWING NOT YET UPDATED FOR MOSAIC-3

Generating a Coverage Map

The code pro/coverage_plot.pro will generate coverage maps for a given date range using the info in mosaic-tiles_obstatus.fits. To run it, login as ??@?? and start IDL:

IDL>.com coverage_plot

To produce the plot for a single night use, for example:

IDL> coverage_plot, datemin='2015-04-07', datemax='2015-04-07'

To produce a plot for a range of nights use:

IDL> coverage_plot, datemin='date-start', datemax='date-end'

To produce a plot for all nights to date use:

IDL> coverage_plot

All plots will be put in $??_OBS/obstatus/Plots. The default is to output a PDF but there are flags to output other formats.

The code pro/coverage_plot_alldates.pro will produce a set of cumulative coverage plots (one per day) over a date range. Within IDL when logged in as ??@?? you enter:

IDL> .com coverage_plot_alldates
IDL> coverage_plot_alldates, datemin='date-start', datemax='date-end'

All plots, consecutively numbered, will be put in $??_OBS/obstatus/Plots/PDFs and can be combined into a movie, e.g with the free graphicconverter ​http://www.lemkesoft.de/en/image-editing-slideshow-browser-batch-conversion-metadata-and-more-on-your-mac/ program on Macs.

Ben Weaver would prefer that we do not upload any plots to SVN but rather just the code. So feel free to mail plots around but there is no need to check them in.

Thank the OA and go to bed

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Pages linking to PublicPages/MayallZbandLegacy/NotesforObservers:

• MayallZbandLegacy
• MayallZbandLegacy/NotesforObservers
• MayallZbandLegacy/ObservingSchedule
• MayallZbandLegacy/Run08
• MayallZbandLegacy/Run13
• PublicPages/MayallZbandLegacy
• PublicPages/MayallZbandLegacy/NotesforObservers/Copilot