Calibrating an EVLA OSRO HI data set

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Revision as of 13:17, 11 February 2010 by Lchomiuk (talk | contribs)
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Overview

Currently, this describes the reduction of the Leo Ring dataset collected with WIDAR0. This page will need to be revised when "real" OSRO data is acquired.

Importing Data

importing data will probably be quirky; let's not discuss the details of this yet.

Get Some Basic Information on Your Data

Use listobs (roughly equivalent to LISTR in AIPS) to list information about your scans, correlator setup, and antenna positions.

#  listobs :: List data set summary in the logger
vis                 = 'leotest.ms'      #  Name of input visibility file (MS)
verbose             =       True
async               =      False        #  If true the taskname must be started using
                                        #   listobs(...)

will produce output that looks like this:

2010-02-11 18:11:34 INFO listobs	##########################################
2010-02-11 18:11:34 INFO listobs	##### Begin Task: listobs            #####
2010-02-11 18:11:34 INFO  	listobs::::casa
2010-02-11 18:11:34 INFO listobs	================================================================================
2010-02-11 18:11:34 INFO listobs	           MeasurementSet Name:  /export/home/rso-lchomiuk/test/Leo/leotest.ms      MS Version 2
2010-02-11 18:11:34 INFO listobs	================================================================================
2010-02-11 18:11:34 INFO listobs	   Observer: leo2pt     Project: T.B.D.  
2010-02-11 18:11:34 INFO listobs	Observation: VLA
2010-02-11 18:11:34 INFO listobs	Data records: 70290       Total integration time = 11264.5 seconds
2010-02-11 18:11:34 INFO listobs	   Observed from   18-Dec-2009/10:52:17.0   to   18-Dec-2009/14:00:01.5 (UTC)
2010-02-11 18:11:35 INFO  	listobs::ms::summary
2010-02-11 18:11:35 INFO listobs	   ObservationID = 0         ArrayID = 0
2010-02-11 18:11:35 INFO listobs	  Date        Timerange (UTC)          Scan  FldId FieldName    nVis   Int(s)   SpwIds
2010-02-11 18:11:35 INFO listobs	  18-Dec-2009/10:52:17.0 - 10:53:45.0     1      0 J1042+1203   660    9.6      [0]
2010-02-11 18:11:35 INFO listobs	              10:54:14.0 - 10:56:51.5     2      1 J1042+1203   1122   9.71     [0]
2010-02-11 18:11:35 INFO listobs	              10:57:20.0 - 11:06:57.5     3      2 Leo-1        3894   9.92     [0]
2010-02-11 18:11:35 INFO listobs	              11:07:25.0 - 11:17:03.0     4      3 Leo-2        3894   9.93     [0]
2010-02-11 18:11:35 INFO listobs	              11:17:32.0 - 11:22:10.0     5      2 Leo-1        1914   9.86     [0]
2010-02-11 18:11:35 INFO listobs	              11:22:39.0 - 11:27:16.5     6      3 Leo-2        1914   9.83     [0]
2010-02-11 18:11:35 INFO listobs	              11:27:45.0 - 11:30:23.5     7      1 J1042+1203   1122   9.82     [0]
2010-02-11 18:11:35 INFO listobs	              11:30:52.0 - 11:40:30.0     8      2 Leo-1        3894   9.93     [0]
2010-02-11 18:11:35 INFO listobs	              11:40:59.0 - 11:50:36.5     9      3 Leo-2        3894   9.92     [0]
2010-02-11 18:11:35 INFO listobs	              11:51:05.0 - 11:55:42.5    10      2 Leo-1        1914   9.83     [0]
2010-02-11 18:11:35 INFO listobs	              11:56:11.0 - 12:00:49.0    11      3 Leo-2        1914   9.86     [0]
2010-02-11 18:11:35 INFO listobs	              12:01:18.0 - 12:03:56.0    12      1 J1042+1203   1122   9.76     [0]
2010-02-11 18:11:35 INFO listobs	              12:04:25.0 - 12:14:03.0    13      2 Leo-1        3894   9.93     [0]
2010-02-11 18:11:35 INFO listobs	              12:14:32.0 - 12:24:09.0    14      3 Leo-2        3894   9.9      [0]
2010-02-11 18:11:35 INFO listobs	              12:24:37.0 - 12:29:15.0    15      2 Leo-1        1914   9.86     [0]
2010-02-11 18:11:35 INFO listobs	              12:29:44.0 - 12:34:21.5    16      3 Leo-2        1914   9.83     [0]
2010-02-11 18:11:35 INFO listobs	              12:34:49.0 - 12:37:28.0    17      1 J1042+1203   1122   9.88     [0]
2010-02-11 18:11:35 INFO listobs	              12:37:57.0 - 12:47:35.0    18      2 Leo-1        3894   9.93     [0]
2010-02-11 18:11:35 INFO listobs	              12:48:04.0 - 12:57:41.5    19      3 Leo-2        3894   9.92     [0]
2010-02-11 18:11:35 INFO listobs	              12:58:10.0 - 13:02:48.0    20      2 Leo-1        1914   9.86     [0]
2010-02-11 18:11:35 INFO listobs	              13:03:17.0 - 13:07:54.5    21      3 Leo-2        1914   9.83     [0]
2010-02-11 18:11:35 INFO listobs	              13:08:23.0 - 13:11:01.5    22      1 J1042+1203   1122   9.82     [0]
2010-02-11 18:11:35 INFO listobs	              13:11:31.0 - 13:21:08.5    23      2 Leo-1        3894   9.92     [0]
2010-02-11 18:11:35 INFO listobs	              13:21:37.0 - 13:31:14.5    24      3 Leo-2        3894   9.92     [0]
2010-02-11 18:11:35 INFO listobs	              13:31:43.0 - 13:36:21.0    25      2 Leo-1        1914   9.86     [0]
2010-02-11 18:11:35 INFO listobs	              13:36:50.0 - 13:41:27.5    26      3 Leo-2        1914   9.83     [0]
2010-02-11 18:11:35 INFO listobs	              13:41:56.0 - 13:44:34.5    27      1 J1042+1203   1122   9.82     [0]
2010-02-11 18:11:35 INFO listobs	              13:48:02.0 - 14:00:01.5    28      4 1331+305     4818   9.99     [0]
2010-02-11 18:11:35 INFO listobs	           (nVis = Total number of time/baseline visibilities per scan) 
2010-02-11 18:11:35 INFO listobs	Fields: 5
2010-02-11 18:11:35 INFO listobs	  ID   Code Name         RA            Decl           Epoch   SrcId nVis   
2010-02-11 18:11:35 INFO listobs	  0    NONE J1042+1203   10:42:44.6052 +12.03.31.2641 J2000   0     660    
2010-02-11 18:11:35 INFO listobs	  1    D    J1042+1203   10:42:44.6052 +12.03.31.2641 J2000   1     6732   
2010-02-11 18:11:35 INFO listobs	  2    NONE Leo-1        10:47:22.0000 +12.16.38.0000 J2000   2     29040  
2010-02-11 18:11:35 INFO listobs	  3    NONE Leo-2        10:46:45.0000 +11.50.38.0000 J2000   3     29040  
2010-02-11 18:11:35 INFO listobs	  4    K    1331+305     13:31:08.2880 +30.30.32.9589 J2000   4     4818   
2010-02-11 18:11:35 INFO listobs	   (nVis = Total number of time/baseline visibilities per field) 
2010-02-11 18:11:35 INFO listobs	Spectral Windows:  (1 unique spectral windows and 1 unique polarization setups)
2010-02-11 18:11:35 INFO listobs	  SpwID  #Chans Frame Ch1(MHz)    ChanWid(kHz)TotBW(kHz)  Ref(MHz)    Corrs   
2010-02-11 18:11:35 INFO listobs	  0         256 TOPO  1415.3756   7.8125      2000        1415.3756   RR  LL  
2010-02-11 18:11:35 INFO listobs	Sources: 6
2010-02-11 18:11:35 INFO listobs	  ID   Name         SpwId RestFreq(MHz)  SysVel(km/s) 
2010-02-11 18:11:35 INFO listobs	  0    J1042+1203   0     -              -            
2010-02-11 18:11:35 INFO listobs	  1    J1042+1203   0     -              -            
2010-02-11 18:11:35 INFO listobs	  2    Leo-1        0     -              -            
2010-02-11 18:11:35 INFO listobs	  3    Leo-2        0     -              -            
2010-02-11 18:11:35 INFO listobs	  4    J1331+3030   0     -              -            
2010-02-11 18:11:35 INFO listobs	  5    J1331+3030   0     -              -            
2010-02-11 18:11:35 INFO listobs	Antennas: 12:
2010-02-11 18:11:35 INFO listobs	  ID   Name  Station   Diam.    Long.         Lat.         
2010-02-11 18:11:35 INFO listobs	  0    ea02  E02       25.0 m   -107.37.04.4  +33.54.01.1  
2010-02-11 18:11:35 INFO listobs	  1    ea03  E09       25.0 m   -107.36.45.1  +33.53.53.6  
2010-02-11 18:11:35 INFO listobs	  2    ea04  W01       25.0 m   -107.37.05.9  +33.54.00.5  
2010-02-11 18:11:35 INFO listobs	  3    ea05  W08       25.0 m   -107.37.21.6  +33.53.53.0  
2010-02-11 18:11:35 INFO listobs	  4    ea08  N01       25.0 m   -107.37.06.0  +33.54.01.8  
2010-02-11 18:11:35 INFO listobs	  5    ea09  E06       25.0 m   -107.36.55.6  +33.53.57.7  
2010-02-11 18:11:35 INFO listobs	  6    ea15  W06       25.0 m   -107.37.15.6  +33.53.56.4  
2010-02-11 18:11:35 INFO listobs	  7    ea19  W04       25.0 m   -107.37.10.8  +33.53.59.1  
2010-02-11 18:11:35 INFO listobs	  8    ea24  W05       25.0 m   -107.37.13.0  +33.53.57.8  
2010-02-11 18:11:35 INFO listobs	  9    ea25  N02       25.0 m   -107.37.06.2  +33.54.03.5  
2010-02-11 18:11:35 INFO listobs	  10   ea27  E03       25.0 m   -107.37.02.8  +33.54.00.5  
2010-02-11 18:11:35 INFO listobs	  11   ea28  N08       25.0 m   -107.37.07.5  +33.54.15.8  
2010-02-11 18:11:35 INFO  	listobs::::casa
2010-02-11 18:11:35 INFO listobs	##### End Task: listobs              #####
2010-02-11 18:11:35 INFO listobs	##########################################

Some things to note here are: The phase calibrator is called J1042+1203, the flux calibrator is 1331+305, and there are two science pointings, Leo-1 and Leo-2.

The correlator is set up in such a way to have one spectral window (or IF). This window is sampled with 256 channels each 7.8 kHz wide. There are no cross-polarization data (note that 'Corrs' is set to only 'RR LL').

Pick a Reference Antenna