Second Shift Checklist
This document is a bare-bones check list for second shift operations. It lists procedures for setting up the work station, for taking over from summit observers, for the observations themselves, and for closing down observations at the end of second shift.
- Setting Up Workspace
- Preparing for Shift Change
- Hand off from Summit
- During 2nd Shift
- Post-Sunrise Point
- Ending Observations
- Useful Links
Second shift observations must be done from the SMA Control Room M343 in Cambridge, or from the Control Room in Taiwan.
Open the following:
- At least two obscon windows, with one or more running monitor
- At least two hal9000 windows, cd into /applications/observingScripts directory, where the observing scripts are found
- orrery from obscon
- Two corrPlotter windows on obscon, one for scan mode, one for mir_mode
- At least one of the web cameras: IR Camera or the Hanger 2 Low Light camera
- SMA OC website: the observing report in one window/tab, maybe the operations log in another and the observing plan page in yet another.
- Message the summit and let observers know you arrived/are getting set up
- Re-read the plan to see what is scheduled for the day
- Glance through current observing report, see if there is anything about which you have questions
- Check "a" and "r" pages on monitor, note antennas in project, anything that may be questionable
- Let summit observers know you are ready to take over
- Ask how night's observations went, if there is anything in particular you should know
- Ask any questions you have about the plan, the status of the array, the script, etc.
- The observers will tell you when they kill the script on their end, and will let you know when you should start the script from Cambridge
- At the appropriate time, restart the script (you should be in the /application/observingScripts directory), usually with the -r flag, which skips the initial calibration check (flux and bandpass) and starts with the source loop. Typing the script name ( scriptName.pl -r ) and hitting return should launch it. If not, you may need a ./ before ( ./scriptName.pl -r)
- Once the script starts, make sure it is doing what you think it should be doing, based on the timeline in the "notes" section of the observing report or on the observing plan page
- Revise the project -- using "project -r" -- to change the observers name (-o) and location (-l) on monitor "a" page
- Put your name as the 2nd shift operator in the observing report (in the "notes" section)
- Let the observers know that you are in control and they are free to head to HP
- Monitor corrPlotter, look for red boxes on scan mode, make sure data is coming in and time is advancing on mir_mode
- Make sure the script advances; look for any errors that may pop up
- About one hour after sunrise, pause script to check pointing. See below for more information.
Once the sun has risen, the dishes will begin to warm and slightly change shape, which will manifest in the observations as pointing errors. Just like during 1st shift observations when we check pointing ~1 hour after sunset (giving the antennas time to cool), during 2nd shift we need to check pointing ~1 hour after sunrise, approximately when the sun reaches an elevation of +15 degrees.
Since some tracks end right around sunrise, pointing won't be done in all cases. A good rule of thumb to follow is: If the source loop of a track ends with one hour of sunrise, do not stop to point. But, if the source loop of a track continues ~1.5 hours or more after sunrise, pause the script ~1 hour after sunrise to point.
For example: On a particular day, sunrise is at 7am HST (17:00 UT). If the source loop of the script ends at 7:45am HST (17:45 UT), do not pause the script and point. But if the source loop continues until 8:25am HST (18:25 UT), make sure you do a post-sunrise ipoint.
If the source loop has ended, but bandpass calibration extends well into daytime, pointing may be beneficial. Just monitor the amplitudes on corrPlotter, and if you have questions ask Shelbi, Taco, or the PI if available.
Guidelines for selecting pointing sources:
- For ipoint: pick a source at least 2 Jy; For cpoint, use a planet
- Choose a source that is in the same area of the sky as the science target
- Choose a source, if possible, at a similar elevation as the science target
- Do not use sources below 20 degrees (unless the science target is extremely low dec)
- Do not use sources above ~70 degrees in elevation
- Do not use sources while they are transiting
Always remember when pausing observations to point, make sure you take some gain cal data before the point and again after the point -- on the same source -- so the PI can track the pointing change.
- run script "endObs" . This will stow the antennas and close the M3 doors. It then does a five minute stability test with the receivers before deactivating the receivers (activate -l 1 -h 5 )
- Verify that the antennas have all reached the stow position (10 az/45 el normally, 10/20 in winter, 10/35 in winter during sub-compact), then issue standby (to turn drives off)
- Close the observing report on the website
- Verify that antennas are in stow position, drives are off and M3 doors are closed, issue endProject
2nd Shift Troubleshooting
Priming
Operating and Priming the SMA
Operational Bad Weather Policies
Polarization Observations