GBT Long-term timing observing instructions

P. Demorest, Nov 18, 2009

Instructions for project 09B-041. See also Ingrid's ASP/GASP instructions. These assume some basic familiarity with GBT pulsar observing. Old 07A-087 instructions are here, but don't use them anymore!

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 09B-041.

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

Open up the Converter Rack page in CLEO.

Configure telescope, adjust scripts

Run either the astrid block Setup_LBand or Setup_800, as appropriate for the day's observing frequency.

Edit the Test_cal scheduling block to use the correct reciever, and pick the appropriate starting source (0218+4232 if it's up, otherwise 0613-0200).

Edit the Observe_loop block to use the correct reciever.

Set up backends

GUPPI: Follow the instructions here to set the input/output levels correctly. See the section labelling "Setting the Levels for GUPPI". The Test_cal block can be used to slew to the first source and take a test cal scan. Once the converter module attenuators are set based on guppi_adc_hist recommendations, it is unlikely the scales will need to be changed.

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 Observe_loop. Note that you first need to uncomment the correct reciever at the top of the script, 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 /tmp/guppi_daq_server.log" will show the output of GUPPI as it is running. Data files will be saved in the usual location depending on your username, project id, etc, 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 GUPPI, and log out of astrid as ususal. GASP still need to be stopped manually:

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