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Auscope Fringe Test

This page describes how the Hobart26m - Hobart12m were carried out.

The system was based on the zero-baselines tests carried out during the commissioning of the Hex cluster (http://www-ra.phys.utas.edu.au/wiki/index.php?n=MtPleasant26m.HexTests9May08). These instructions are now seriously out of date.

  • Prepare Vex file - using zero2.skd as a template (~observer/correlations/zero_baseline2/). Updated the time settings in the $SCHED section, fixed the $FREQ section to ensure that the info reflects the lower band-edges and that the BBC mapping is correct.
  • Update the EOP parameters using update_epoc on hex0 (This script has been updated and now works)
  • vex2model_updated.pl zero3.skd
  • vex2config.pl -nchan 1024 -int 1 -evlbi zero3.skd
  • Edit the zero3.input file to update the #NETWORK TABLE, setting

PORT NUM 0: 52100
PORT NUM 1: 52101

You might also want to edit the TSYS values for the different telescopes if you're using non-standard telescope IDs.

  • Copy the run.sh executable, machines and threads files from a previous experiment (such as ~observer/correlations/zero_baselines3/run.sh , ~observer/correlations/zero_baselines3/machines and ~observer/correlations/zero_baselines3/threads) and edit it to use zero3.input. This file is set up to not use hex1 (which is currently out of service) and is also set to use 7/8 cores of each computer, rather than 8/8. This is because leaving one core to handle I/O functions leads to better performance.
  • Check the .uvw file for ^P
  • Then run the executable with ./run.sh . It will run and later stall, while waiting for a connection. This is ok.
  • On hovsi, run

vsib_record -t 300s -host 131.217.63.210 -port 52100 -host2 131.217.63.210 -port2 52101

This will start the recorder and start send the data to the correlator directly. The output of run.sh should start updating. Check that the PPS, BIGBUF and sampler statistics from the recorder are ok.

  • You can monitor the output of the correlator from hex. Start two xterms on hex0. In one, run monitor_server 9999 and in the other run mon_sample localhost zero3.input 0 1 . This will start a PGPLOT window that will show the latest cross-correlation in amplitude, phase and delay. This takes a little while to start.