Data flagging with viewer: Difference between revisions
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Your data will inevitably have some bad data. Perhaps a receiver on a given antenna is acting up, or perhaps the pointing on a given antenna is poor, and these problematic data will translate to (hopefully) obviously aberrant data in your measurement set. It's a good idea to inspect your data carefully before calibration and imaging, and CASA offers several tools to flag bad data interactively. | Your data will inevitably have some bad data. Perhaps a receiver on a given antenna is acting up, or perhaps the pointing on a given antenna is poor, and these problematic data will translate to (hopefully) obviously aberrant data in your measurement set. It's a good idea to inspect your data carefully before calibration and imaging, and CASA offers several tools to flag bad data interactively. | ||
This tutorial illustrates how to use [[viewer]] to flag poor data. It will use the dataset [https://archive.nrao.edu/archive/ArchiveQuery?PASSWD=&QUERYTYPE=ARCHIVE&PROTOCOL=HTML&SORT_PARM=Starttime&SORT_ORDER=Asc&MAX_ROWS=NO+LIMIT&SORT_PARM2=Starttime&SORT_ORDER2=Asc&QUERY_ID=9999&QUERY_MODE=Prepare+Download&LOCKMODE=PROJECT&SITE_CODE=AOC&DBHOST=CHEWBACCA&WRITELOG=0&PROJECT_CODE=AU0079&SEGMENT=&OBSERVER=&ARCHIVE_VOLUME=&TIMERANGE1=&TIMERANGE2=&SOURCE_ID=&SRC_SEARCH_TYPE=SIMBAD+or+NED+Resolver&CALIB_TYPE=ALL+Srcs&CENTER_RA=&LONG_RANGE=&FRAME=Equatorial&CENTER_DEC=&LAT_RANGE=&EQUINOX=J2000&SRAD=1.0%27&MIN_EXPOSURE=&OBS_BANDS=L&TELESCOPE=VLA&OBS_MODE=ALL&CORR_MODE=ALL&TELESCOPE_CONFIG=A&OBS_POLAR=ALL&OBSFREQ1=&DATATYPE=ALL&OBSBW1=&ARCHFORMAT=ALL&SUBMIT=Submit+Query AU079] from the VLA archive; this dataset is also used in the [[Imaging Flanking Fields]] tutorial. As described in that tutorial, the data may be loaded into CASA | This tutorial illustrates how to use [[viewer]] to flag poor data. It will use the dataset [https://archive.nrao.edu/archive/ArchiveQuery?PASSWD=&QUERYTYPE=ARCHIVE&PROTOCOL=HTML&SORT_PARM=Starttime&SORT_ORDER=Asc&MAX_ROWS=NO+LIMIT&SORT_PARM2=Starttime&SORT_ORDER2=Asc&QUERY_ID=9999&QUERY_MODE=Prepare+Download&LOCKMODE=PROJECT&SITE_CODE=AOC&DBHOST=CHEWBACCA&WRITELOG=0&PROJECT_CODE=AU0079&SEGMENT=&OBSERVER=&ARCHIVE_VOLUME=&TIMERANGE1=&TIMERANGE2=&SOURCE_ID=&SRC_SEARCH_TYPE=SIMBAD+or+NED+Resolver&CALIB_TYPE=ALL+Srcs&CENTER_RA=&LONG_RANGE=&FRAME=Equatorial&CENTER_DEC=&LAT_RANGE=&EQUINOX=J2000&SRAD=1.0%27&MIN_EXPOSURE=&OBS_BANDS=L&TELESCOPE=VLA&OBS_MODE=ALL&CORR_MODE=ALL&TELESCOPE_CONFIG=A&OBS_POLAR=ALL&OBSFREQ1=&DATATYPE=ALL&OBSBW1=&ARCHFORMAT=ALL&SUBMIT=Submit+Query AU079] from the VLA archive; this dataset is also used in the [[Imaging Flanking Fields]] tutorial. As described in that tutorial, the data may be loaded into CASA using the [[importvla]] command. The following commands import the data into the measurement set ''au079.ms'' and send them to the viewer. | ||
<source lang="python"> | <source lang="python"> | ||
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importvla(archivefiles=fileList,vis='au079.ms') | importvla(archivefiles=fileList,vis='au079.ms') | ||
viewer('au079.ms') # load the data into the viewer for editing | |||
</source> | </source> | ||
--[[User:Jgallimo|Jgallimo]] 19:14, 23 November 2009 (UTC) | --[[User:Jgallimo|Jgallimo]] 19:14, 23 November 2009 (UTC) | ||
Revision as of 19:15, 23 November 2009
Your data will inevitably have some bad data. Perhaps a receiver on a given antenna is acting up, or perhaps the pointing on a given antenna is poor, and these problematic data will translate to (hopefully) obviously aberrant data in your measurement set. It's a good idea to inspect your data carefully before calibration and imaging, and CASA offers several tools to flag bad data interactively.
This tutorial illustrates how to use viewer to flag poor data. It will use the dataset AU079 from the VLA archive; this dataset is also used in the Imaging Flanking Fields tutorial. As described in that tutorial, the data may be loaded into CASA using the importvla command. The following commands import the data into the measurement set au079.ms and send them to the viewer.
# from loaddata.py
from glob import glob
# Define the list of files for reading. Use glob to perform wildcard matching with VLA archive filenames.
fileList = glob('AU079_*.xp?')
importvla(archivefiles=fileList,vis='au079.ms')
viewer('au079.ms') # load the data into the viewer for editing
--Jgallimo 19:14, 23 November 2009 (UTC)
