NRAO Home  >  Green Bank  |  Wiki Topic:    GB > Pennarray > OrionPlan

Changes | Index | Contents | Search | Go

Early Science Runs

The science SBs are in project AGBT08A_056

Operator is at 3044562341 -- also on CLEO Talk & Draw

Notes

• 22feb08 bsm -- There's a patch to the active surface positions that we should try the next run. The one row of actuators down the middle have had bogus settings up till now, a fact that Fred Schwab discovered recently. Reactivate old model when done. Brian has the procedures to do this.
• 25feb08 bsm -- I rotated the focusdaisies SB so that there is a lobe pointing 'up'.
• 05mar08 bsm -- we should try a daisy suited to OOF -- +/-9mm, lissdaisy, more coverage than usual (120 sec radpd=20sec) -- on Mars and/or 3c279

Observing Procedures

If possible we should carry out a full cycle some time before midday or a quick cycle that finishes around 4:00pm

1. Try and tune up the receiver an hour or so before observing begins
   • Do firmware ramp
   • rough bias using cal
2. If observing remotely, you'll need to tunnel in to a gbt network machine (which is within the gb network) and fire up vnc. The generic instructions are here. Note that I always recommend you use a password you are willing to share with others -- and fire up vncserver with "-alwaysshared" option. My preferred method for vnc tunneling is described at BriansVncMethod. Good machines on the gbt network are ariel and titania.
3. Within your gbt network session you will want to launch astrid and cleo, from the command line. Before you do this be sure to "source /home/gbt/gbt.csh" (or .bash). Once you have CLEO up you'll want a number of windows; an easy way to do this is to Launch->cleo Container. Then from the container window, File->Launch List of Applications. Navigate to and choose ~bmason/mustangPub/mustangcleo.ccf
4. Once we have control of the telescop: Have the operator turn the blower off (see also policy at the end of this list)
   • verify that LPCs, LFCs (including tilts) are zeroed
   • active surface on and happy (quick-set on now works) -- 2005WinterV2. Check by verifying that the Zernike Coefficients are updating. Should be automatic.
   • dynamic corrections on and updating -- there will be a warning message if they are not...
   • pointing model 4C. should be automatic.
5. Take blank & cal file - check we have 57 good detectors. Always use a 1.2Volt Cal
6. First focus on planet for calibration
   • focus daisy parameters: scan duration=45 sec; daisy radius=0.75'; daisy radial period=20 sec.
   • suggested focus sampling: [-7,-3,0,3,7]mm relative to current nominal. assume nominal is 0mm to start with.
   • do a quick daisy at best focus. Parameters: scan duration=90 sec; radius=1'; period=30 sec.
   • do a very fast daisy at best focus so as to have a check on our timestamping alignment after the fact. Parameters: same as quick daisy but use 10 sec instead of 30 sec period.
7. To analyze the data, you can use ~bmason/mustangPub/mustangidl (which is just a wrapper for regular IDL). If you want to use the IDLDE that's probably ok but I don't guarantee it-- then you just need to ensure that ~bmason/mustangidlbin/ and all its subdirectories are in your path (and that no files in your regular IDL path with the same name come before it!!). An annotated script with examples of how to observe can be seen at ~bmason/mustangidlbin/reg/demo-map.pro (and demo-lab.pro for lab-type stuff -- plotting firmware ramps, deriving shunts, etc)
8. Move to secondary calibrator (for Orion: 0530+135) check focus +-8mm.
9. Take care that you LEAVE the focus in the good position not the endpoint of the checkfocus. parfocusdaisies has a parameter called finalfocus for this purpose. You can also use SB applypointing which applied pointing and focus offsets -- however except in the most extreme cases I suggest we avoid applying the pointing offsets, it's probably better to do these offline.
10. collect blank and cal
11. relock detectors
12. Obseve orion -- observe fields bolorionN2 (note that's N2 not N) and bolorionS. Spend twice as much time on N2 as S. Use boxmap SB with the 5'x5' pattern: parameters are x0=5, y0=5; taux=9,tauy=9; scan duration=290 sec; nrepeat=3; tstart=0. One scan takes ~5 min, so with nrepeat=3 one SB takes 15 minutes -- you can do two such SBs before you need to check the focus again. Note that the dither pattern is linked to nrepeat and only change with care.
13. after a half hour of observing:
    • relock;
    • go back to calibrator to check focus; use same parameters for focus daisies as before, adjusting focus array as needed. remember to leave the focus near th optimal position in the focusdaisy SB and/or apply the determined focus with SB applyptg.
    • collect blank and cal;
14. Make maps as we go along, keep an eye out for noise & unlocked detectors. Keep an observing log noting data quality and anomalies, weather, sources observed and scan patterns used, etc.
15. Blower policy: within the last hour of observing, if the temperature has dropped from above to below zero during the run, OR if within 3 degrees of the dewpoint and above freezing -- run the blower

WARNING/HAZARDS/THINGS TO WATCH

• Never apply more than 1.4 volts to the cal. 2 Volts can burn it out - you should always use 1.2 V anyway...
• Keep notes in the usual area (/home/scratch/sdicker/data_analysis)
• At the end of your run summarize data collected in the table on this page

Target Selection

Data Collected

-- SimonDicker - 31 Jan 2008