CASA EVLA Tasks
CASA Contributed Task: listsdm
CASA Contributed Task: findsources
CASA Contributed Tasks: Overview
Overview
This is a collection of CASA tasks to help process and analyze EVLA data. Although they are not officially supported, some authors may choose to provide contact information.
Since they are CASA tasks, you will need to run the buildmytasks application prior to importing into CASA. See Appendix G of the CASA Cookbook for a description of this process. Note that as a result of posting these files to a Wiki, the names have been changed so that the first letter is capitalized. You will need to change this to lowercase prior to running buildmytasks. Once imported, they are called like any other tasks, and will include help information within CASA.
Note that you may also set up CASA to auto-import external tasks built with buildmytasks. To do this, create a directory called .casa in your home directory. Within that directory, create a file called init.py containing the line "execfile('<path to mytasks.py>')", where "mytasks.py" is created by the buildmytasks command.
If you would like to contribute, and do not have access to the CASA Guides WIKI, you may email Miriam Krauss (mkrauss at nrao.edu).
stitch: combine data taken in an overlapping-subband mode
Please see the complete tutorial, Baseband Stitching-CASA4.1, for the task files and a description of how to use stitch to edit data which was acquired in an overlapping-subband mode.
listsdm: a 'listobs'-style information tool for SDM files
Download task files: task_listsdm.py, listsdm.xml
This task lists information directly from the SDM directory's XML tables and prints this information to the CASA log. Formatting is similar to the task listobs; however, listsdm is much faster for larger datasets, and can be run before (or while) importing to an MS.
It will also return a dictionary keyed on scan number. The dictionary contains the following information, which can be useful for scan selection prior to import:
'baseband' list of baseband name(s)
'chanwidth' list of channel widths (Hz)
'end' observation end time (UTC)
'field' field ID
'intent' scan intent(s)
'nchan' list of number of channels
'nsubs' number of subscans
'reffreq' list of reference frequencies (Hz)
'source' source name
'spws' list of spectral windows
'start' observation start time (UTC)
'timerange' start time - end time range (UTC)
# In CASA
myScanDict = listsdm('mySDMfile')
Representative log output:
2011-01-02 02:26:32 INFO listsdm ================================================================================ 2011-01-02 02:26:32 INFO listsdm SDM File: AS1039_sb1382796_2_000.55368.51883247685 2011-01-02 02:26:32 INFO listsdm ================================================================================ 2011-01-02 02:26:32 INFO listsdm Observer: Michael P. Rupen 2011-01-02 02:26:32 INFO listsdm Facility: EVLA, D-configuration 2011-01-02 02:26:32 INFO listsdm Observed from 2010/06/21/12:27:08.17 to 2010/06/21/13:26:55.70 (UTC) 2011-01-02 02:26:32 INFO listsdm Total integration time = 3587.53 seconds (1.00 hours) 2011-01-02 02:26:32 INFO listsdm 2011-01-02 02:26:32 INFO listsdm Scan listing: 2011-01-02 02:26:32 INFO listsdm Timerange (UTC) Scan FldID FieldName SpwIDs Intent(s) 2011-01-02 02:26:32 INFO listsdm 12:27:08.17 - 12:28:05.36 1 0 J2038+5119 [0, 1] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:28:05.36 - 12:29:05.20 2 0 J2038+5119 [2, 3] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:29:05.20 - 12:30:05.04 3 0 J2038+5119 [0, 1] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:30:05.04 - 12:36:04.05 4 1 V407 Cyg+4amin [0, 1] OBSERVE_TARGET 2011-01-02 02:26:32 INFO listsdm 12:36:04.05 - 12:37:23.83 5 0 J2038+5119 [0, 1] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:37:23.83 - 12:50:21.71 6 1 V407 Cyg+4amin [0, 1] OBSERVE_TARGET 2011-01-02 02:26:32 INFO listsdm 12:50:21.71 - 12:51:41.49 7 0 J2038+5119 [0, 1] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:51:41.49 - 12:53:01.27 8 2 J2048+4310 [2, 3] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 12:53:01.27 - 12:59:00.29 9 3 V407 Cyg+1amin [2, 3] OBSERVE_TARGET 2011-01-02 02:26:32 INFO listsdm 12:59:00.29 - 13:00:20.07 10 2 J2048+4310 [2, 3] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 13:00:20.07 - 13:06:19.08 11 3 V407 Cyg+1amin [2, 3] OBSERVE_TARGET 2011-01-02 02:26:32 INFO listsdm 13:06:19.08 - 13:07:38.86 12 2 J2048+4310 [2, 3] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 13:07:38.86 - 13:13:37.88 13 3 V407 Cyg+1amin [2, 3] OBSERVE_TARGET 2011-01-02 02:26:32 INFO listsdm 13:13:37.88 - 13:14:57.66 14 2 J2048+4310 [2, 3] CALIBRATE_PHASE 2011-01-02 02:26:32 INFO listsdm 13:14:57.66 - 13:19:56.84 15 4 J0137+3309 [0, 1] CALIBRATE_PHASE UNSPECIFIED CALIBRATE_BANDPASS CALIBRATE_AMPLI 2011-01-02 02:26:32 INFO listsdm 13:19:56.84 - 13:21:56.52 16 4 J0137+3309 [2, 3] CALIBRATE_PHASE UNSPECIFIED CALIBRATE_BANDPASS CALIBRATE_AMPLI 2011-01-02 02:26:32 INFO listsdm 13:21:56.52 - 13:24:56.02 17 5 J0319+4130 [0, 1] CALIBRATE_PHASE CALIBRATE_BANDPASS UNSPECIFIED 2011-01-02 02:26:32 INFO listsdm 13:24:56.02 - 13:26:55.70 18 5 J0319+4130 [2, 3] CALIBRATE_PHASE CALIBRATE_BANDPASS UNSPECIFIED 2011-01-02 02:26:32 INFO listsdm 2011-01-02 02:26:32 INFO listsdm Spectral window information: 2011-01-02 02:26:32 INFO listsdm SpwID #Chans Ch0(MHz) ChWidth(kHz) TotBW(MHz) Baseband 2011-01-02 02:26:32 INFO listsdm 0 64 1388.0 2000.0 128.0 BB_4 2011-01-02 02:26:32 INFO listsdm 1 64 1756.0 2000.0 128.0 BB_8 2011-01-02 02:26:32 INFO listsdm 2 64 4736.0 2000.0 128.0 BB_4 2011-01-02 02:26:32 INFO listsdm 3 64 7836.0 2000.0 128.0 BB_8 2011-01-02 02:26:32 INFO listsdm 2011-01-02 02:26:32 INFO listsdm Field information: 2011-01-02 02:26:32 INFO listsdm FldID Code Name RA Dec SrcID 2011-01-02 02:26:32 INFO listsdm 0 D J2038+5119 20:38:37.03 +051.19.12.663 0 2011-01-02 02:26:32 INFO listsdm 1 NONE V407 Cyg+4amin 21:02:09.80 +045.50.32.980 1 2011-01-02 02:26:32 INFO listsdm 2 D J2048+4310 20:48:19.53 +043.10.42.073 2 2011-01-02 02:26:32 INFO listsdm 3 NONE V407 Cyg+1amin 21:02:09.80 +045.47.32.980 3 2011-01-02 02:26:32 INFO listsdm 4 Z J0137+3309 01:37:41.30 +033.09.35.133 4 2011-01-02 02:26:32 INFO listsdm 5 Z J0319+4130 03:19:48.16 +041.30.42.103 5 2011-01-02 02:26:32 INFO listsdm 2011-01-02 02:26:32 INFO listsdm Antennas (26): 2011-01-02 02:26:32 INFO listsdm ID Name Station Diam.(m) Lat. Long. 2011-01-02 02:26:32 INFO listsdm 0 ea01 W09 25.0 +000.00.00.0 +000.00.00.0 2011-01-02 02:26:32 INFO listsdm 1 ea02 E02 25.0 +033.53.51.0 -107.37.25.2 2011-01-02 02:26:32 INFO listsdm 2 ea03 E09 25.0 +033.54.01.1 -107.37.04.4 2011-01-02 02:26:32 INFO listsdm 3 ea04 W01 25.0 +033.53.53.6 -107.36.45.1 2011-01-02 02:26:32 INFO listsdm 4 ea05 W08 25.0 +033.54.00.5 -107.37.05.9 2011-01-02 02:26:32 INFO listsdm 5 ea08 N01 25.0 +033.53.53.0 -107.37.21.6 2011-01-02 02:26:32 INFO listsdm 6 ea09 E06 25.0 +033.54.01.8 -107.37.06.0 2011-01-02 02:26:32 INFO listsdm 7 ea10 N03 25.0 +033.53.57.7 -107.36.55.6 2011-01-02 02:26:32 INFO listsdm 8 ea11 E04 25.0 +033.54.04.8 -107.37.06.3 2011-01-02 02:26:32 INFO listsdm 9 ea12 E08 25.0 +033.53.59.7 -107.37.00.8 2011-01-02 02:26:32 INFO listsdm 10 ea13 N07 25.0 +033.53.55.1 -107.36.48.9 2011-01-02 02:26:32 INFO listsdm 11 ea14 E05 25.0 +033.54.12.9 -107.37.07.2 2011-01-02 02:26:32 INFO listsdm 12 ea15 W06 25.0 +033.53.58.8 -107.36.58.4 2011-01-02 02:26:32 INFO listsdm 13 ea16 W02 25.0 +033.53.56.4 -107.37.15.6 2011-01-02 02:26:32 INFO listsdm 14 ea17 W07 25.0 +033.54.00.9 -107.37.07.5 2011-01-02 02:26:32 INFO listsdm 15 ea18 N09 25.0 +033.53.54.8 -107.37.18.4 2011-01-02 02:26:32 INFO listsdm 16 ea19 W04 25.0 +033.54.19.0 -107.37.07.8 2011-01-02 02:26:32 INFO listsdm 17 ea20 N05 25.0 +033.53.59.1 -107.37.10.8 2011-01-02 02:26:32 INFO listsdm 18 ea21 E01 25.0 +033.54.08.0 -107.37.06.7 2011-01-02 02:26:32 INFO listsdm 19 ea22 N04 25.0 +033.53.59.2 -107.37.05.7 2011-01-02 02:26:32 INFO listsdm 20 ea23 E07 25.0 +033.54.06.1 -107.37.06.5 2011-01-02 02:26:32 INFO listsdm 21 ea24 W05 25.0 +033.53.56.5 -107.36.52.4 2011-01-02 02:26:32 INFO listsdm 22 ea25 N02 25.0 +033.53.57.8 -107.37.13.0 2011-01-02 02:26:32 INFO listsdm 23 ea26 W03 25.0 +033.54.03.5 -107.37.06.2 2011-01-02 02:26:32 INFO listsdm 24 ea27 E03 25.0 +033.54.00.1 -107.37.08.9 2011-01-02 02:26:32 INFO listsdm 25 ea28 N08 25.0 +033.54.00.5 -107.37.02.8
An entry from the scan dictionary:
CASA <16>: myScanDict
Out[16]:
{1: {'baseband': ['BB_4', 'BB_8'],
'chanwidth': [2000000.0, 2000000.0],
'end': '2010/06/21/12:28:05.36',
'field': 0,
'intent': 'CALIBRATE_PHASE',
'nchan': [64, 64],
'nsubs': 1,
'reffreq': [1388000000.0, 1756000000.0],
'source': 'J2038+5119',
'spws': [0, 1],
'start': '2010/06/21/12:27:08.17',
'timerange': '2010/06/21/12:27:08.17~2010/06/21/12:28:05.36'},
findsources: use the online Vizier catalogs to find sources for outlier-field imaging
Download task files: File:Task findsources.py, File:Findsources.xml
This task queries any VizieR catalog around coordinates defined by either the phase center of a source in the input visibility file or an input RA/Dec pair. It creates an outlier file which can be used by clean to create images of flanking fields. This is particularly useful if there is a bright source relatively nearby which would create imaging artifacts if ignored. (Note that some catalog abbreviations are ambiguous: in this case, use the full catalog name, or VizieR will query multiple catalogs.)
