GBT Long-term timing observing instructions

P. Demorest, July 15, 2009

NOTE: These instructions are obsolete! New ones are available here.

Instructions for project 07A-087. See also Ingrid's ASP/GASP instructions. These assume some basic familiarity with GBT pulsar observing.

Pre-Observing setup

Start up VNC, astrid, cleo and talk-n-draw in the usual way. Some more detailed instructions on how to do this appear here. Note that the current project ID is 07A-087.

Open up several gasp@gasp0 xterms (for GASP) and several beef xterms (for GUPPI).

Open up the Converter Rack page in CLEO.

Configure telescope

Run either the astrid block A_setup_GASP+Spigot_1400 or A_setup_GASP+Spigot_800, as appropriate for the day's observing frequency. Note: We will not actually be using Spigot, but these blocks also route the signals to GUPPI.

Set up backends

IMPORTANT: Do not do any of the following unless you are sure no one is currently observing with GUPPI or GASP. Check the telescope schedule, and if in doubt, just wait until your scheduled time starts.

GUPPI: Follow the instructions here to configure GUPPI and get the input/output levels set correctly. For this project, we use the following settings:

GASP: Run "setif GBT" on gasp0. Check GASP signal levels by logging into cpci from gasp0 (ssh cpci -l root), then running rms. Input power can be adjusted using set_gain and read_gain on cpci, or by changing the attenuator values for Converter Modules 11 and 15 in CLEO.

Start observing script

Run the astrid block New_Schedule_1400_guppi or New_Schedule_800_guppi, depending on the band in use. This will automatically run through our list of sources (the schedule is in ~pdemores/sched/, taking cal and pulsar scans with both backends. Assuming everything works, no further action should be needed until the end of the session.

Checking status/results

GASP: Run stat_msg on gasp0 to see GASP status messages. This can be left running throughout the session. To see the real-time folded profile display, run stat_asp on gasp0 as usual. This should only be run while data is being taken (after the "Start MJD = ..." message) and will exit automatically when the current pulsar is finished. Data files are saved in /home/gasp/data/GBT07A-087.

GUPPI: Run guppi_status as usual to see the current GUPPI settings. guppi_monitor can be run at any time during observing to see the current bandpass. "tail -f /data1/demorest/guppi.log" will show the output of guppi_fold as it is running. Data files will be saved in /data1/demorest/guppi_data/GBT_NANOGrav_(date) and can be examined/viewed with psrchive commands (vap, pav, etc).

Stopping observations

At the end of the session, press "Abort" in astrid to stop the observing script, and log out of astrid as ususal. The backends still need to be stopped as well:

GASP: Just run stop_asp on gasp0 and also control-C any stat_msg processes.

GUPPI: Run "pkill -INT guppi_daq" on beef. HOWEVER, since the datataking processes for the script run as user pdemores, this will need to be done from a pdemores login (or as root, if you have sudo access). I'll set up a VNC session and send email on how to log into it so this can be done. Yes, this is a pretty ugly hack.. hopefully a better way will be available soon!