Spigot obs with Astrid

Date: Wed, 9 Nov 2005 15:48:47 -0500
From: Scott Ransom
Subject: Astrid Intro
Resent-Date: Thu, 10 Nov 2005 14:49:25 -0500

Hey All,

OK. So here is a limited intro to Astrid for you. I would recommend the following.

1. Quickly read the following two web pages to get acquainted with what Astrid is all about: http://wiki.gb.nrao.edu/bin/view/Data/AstronomersIntegratedDesktop http://wiki.gb.nrao.edu/bin/view/Software/ObservingTools
2. Login to a GB machine via VNC and take a look at some of my Spigot scheduling blocks and play around with the interface a bit (see below).

Here is what I would do for #2:

• Login to GB (ssh.gb.nrao.edu) and then to titania or naiad (those are the observing machines). If you are not observing I would recommend naiad since that machine is not used as often for real observing).
• From that machine start: vncserver -depth 8 geometry 1200x900 (feel free to edit the depth and geometry)
• Then on your home machine run: vncviewer -via [your username]@ssh.gb.nrao.edu titania:1 (or whatever the display number is).
• Modern (2006): Run ~sransom/bin/myastrid to get paths set up right when starting astrid.
  Historical (2005): From there, in some terminal, do the following assuming that bash is your shell (just to be safe):
  export PYTHONPATH=
  export PGPLOT_DEV=
  export PGPLOT_DIR=
  export LD_LIBRARYPATH=
  These are currently needed in case your environment has PRESTO capability. PRESTO uses a different version of PGPLOT than astrid's graphical display, and astrid will SEGFAULT if it gets the wrong one during the AutoPeak() scan. Then start astrid (it is called astrid) from that window.
• For now, select the "work-offline" mode. You would choose one of the other modes if you were actually going to observe (and had been placed in the "gateway" by the operator). You can change your mode later from the File->"Real Time Mode" menu option.
• In the main window, select the "Edit" tab and choose project GBT05C-042. You can click on each of the various scheduling blocks that are displayed and they will show up in the editor window. I've labeled them with A*, B*, C* etc to show you the way that you would submit them during an real observation. So take a look at them in that order.
• In general, for a simple Spigot-based pulsar observation we do:
  1. Slew to a test pulsar
  2. Perform an AutoPeakFocus() which will determine pointing and focus corrections with respect to the currently used pointing model of the telescope based on scans on a nearby (to the test pulsar) continuum calibrator. This scan is useful for L-band and higher frequency (skip it for prime focus). When you run this in real-life the DataDisplay tab will show you plots of the scans and after 4 of them (for pointing) are done, you will see a set of corrections in Az and El (daz, del) in arcmin. Those values should almost always be a small fraction of an arcmin. If they are not, there is probably a problem with the pointing model (talk to the operator). You will also get rough values for the system temperature.
  3. Slew back to the test pulsar
  4. Balance the system (Note: for prime focus work you also need to specifically focus the PF1 receiver. See the "*balance" scheduling blocks for GBT05C-045 for an example of that.) Make sure that the levels are OK and the spectrometer duty cycles are ~0.8. See my old notes for details.
  5. Start the autoleveler (_outside_ of astrid as per the old spigot notes).
  6. Configure the system for Spigot (or BCPM+Spigot, or Spigot+GASP) usage.
  7. Setup the spigot (for this you need to specify a data directory on the spigot2 machine. NOTE: this directory should _not_ already exist. Astrid will create it for you. If you want to create it yourself, make sure that its permissions are 1777).
  8. Take a short test scan and then fold it on the spigot2 machine with prepfold.
  9. Slew to your science source and balance the IFRack (and PF1 receiver if necessary).
  10. Take science data.
  11. For multiple scans using user generated catalogs etc, check out the "spigot_dosurvey" scheduling block in project GBT05C-045

You can also switch back and forth between the "Edit" and "Run" tabs if you need to change a scheduling block or two. Scheduling blocks can be copied between projects and they can be imported/exported as text files as well. They can use pretty much any legal python in them (and there are lots of modules available as well). Hit the "Validate" button to check your syntax before saving. One last thing to mention is that you have to make sure to enter your name as the Observer and the telescope operator's name in the Operator space before you submit your first scheduling block.

Feel free to poke around and look at scheduling blocks from other proposals as well. Toney Minter has some pretty sophisticated scheduling blocks in GBT05C-049 that show user defined scan types and how to import special python libraries.

Let me know if you have any questions,

Scott