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operation:fringe_checking

Introduction

A simple script (adapted from the ATNF's RtFC suite) is now available for carrying out fringe-checks between the AuScope antennas. The script creates a schedule, carries out the observation, correlates the data on the hex cluster and finally carries out the fringe search on the correlated data. A major caveat is that it does not make any attempt to configure the backend or recorders, and assumes that the recording mode is set to the standard R1/R4/aust geodetic configuration. As such, it's probably best to use this script after going through the Auscope checklist for each telescope first. If a non-standard configuration is desired, it's probably best to create a proper VEX schedule and use that.

Running the script

Note: You need atleast a baseline between two dishes to get fringes. Skip this step if only using one telescope

Firstly, if there are any apparent problems, the script can be efficiently stopped with ctrl-c commands. It should not be necessary to do this except in the event of an antenna/recorder error.

The script (fcgeo.sh) is located on hex0 in the /home/observer/fc_auscope/ subdirectory. Log on to hex0 as observer (the usual password). It should be started with the command

./fcgeo.sh hb ke yg
 ./fcgeo.aust.sh hb ke yg (for austral observations)

(a maximum of three telescopes can be scheduled at once with the current script). It will then issue a warning about requiring the stanadrd geodetic configuration. If Yarragadee is scheduled, it will prompt the user to check that the USN transmitter is not active.

Once started, it will select a suitable fringefinder (either 0537-441, 3C273 or 1921-293 at present) and issue source=… commands to all the telescopes via ssh. Once all telescopes report their status as “TRACKING”, timed disk_record and disk2file commands are issued. The exported spectest.m5b files are scp'd back to hex0 and renamed appropriately.

Once all the data is available on hex0, the script creates suitable vex and v2d files and then processes them through DiFX. All the files are kept in ~observer/fc_auscope/tmp/ with the root name of fcyyyydddhhmm where yyyy, ddd, etc are the UT time of the recordings. The data files are kept as $exper$station.m5b in this directory also.

When everything is ready, the script launches DiFX's errormon2, and will then run the correlation. Once complete, it will then run the fringe_find program for each correlated baseline (reporting back the results in the terminal window) and also producing eps plots of each frequency channel per baseline. These are stored in ~observer/fc_auscope/ View the eps plots using, on hex0,

gv [filename] 

From top left to lower right, the first 10 channels are X-band and the last six are S-band.

/home/www/auscope/opswiki/data/pages/operation/fringe_checking.txt · Last modified: 2016/04/21 08:55 by Arwin Kahlon