CASA EVLA Tasks

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CASA Contributed Task: stitch

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.)