[daip] Potential LISTR Bug

Amanda Kepley kepley at astro.wisc.edu
Mon Nov 26 12:00:16 EST 2007


To whom it may concern:

I've uncovered a possible bug in LISTR when using OPTYPE='MATX' and  
STOKES='POLC' with multiple IFs. I'm currently calibrating some 13cm  
WSRT data in AIPS. (The 13cm feed at WSRT is the only circularly  
polarized feed at WSRT so you don't need to do anything special in  
AIPS to calibrate this data). This data has 8 IFs. When I run LISTR  
on polarization calibrated data with bif=1;eif=8, I get a consistent  
R-L angle for all antennas for IF 1, but not for IFs 2 through 8.  
However, when I run each IF separately through LISTR (e.g.  
bif=2;eif=2), I get a consistent R-L angle for all antennas in each IF.

See below for some example code. I'm using AIPS version 31DEC07.

Cheers,

Amanda

------------------------------------------------------------------------ 
-------------------------------

Doing LISTR on all IFs at once:

AIPS 1: LISTR:  Task to print UV data and calibration tables.
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: USERID      333                    User number.
AIPS 1: INNAME     'N1569'                 UV data (name).
AIPS 1: INCLASS    'DAY1C'                 UV data (class).
AIPS 1: INSEQ         1                    UV data (seq. #).  0 => high
AIPS 1: INDISK        4                    Disk unit #.       0 => any
AIPS 1: OPTYPE     'MATX'                  List type:
AIPS 1:                                     'MATX','LIST','GAIN','SCAN'
AIPS 1: INEXT      'CL'                    CL, SN or TY table for 'GAIN'
AIPS 1: INVER         0                    CL, Sn or TY table version
AIPS 1: SOURCES    '3C286'                 Source list
AIPS 1:            *rest ' '
AIPS 1: CALCODE    ' '                     Calibrator code '    '=>all
AIPS 1: TIMERANG   *all 0                  Time range to list
AIPS 1: STOKES     'POLC'                  Stokes type to list.
AIPS 1: SELBAND      -1                    Bandwidth to select (kHz)
AIPS 1: SELFREQ      -1                    Frequency to select (MHz)
AIPS 1: FREQID       -1                    Freq. ID to select.
AIPS 1:                                    None selected => 1.
AIPS 1: BIF           0                    Lowest IF number 0=1
AIPS 1: EIF           0                    Highest IF number
AIPS 1: BCHAN         1                    Low channel number 0=>1
AIPS 1: ECHAN         0                    High channel number
AIPS 1: ANTENNAS   *all 0                  Antennas to list
AIPS 1: BASELINE   *all 0                  Baselines with ANTENNAS
AIPS 1: UVRANGE       0           0        UV range in kilolambda
AIPS 1: SUBARRAY      0                    Subarray, 0=>1
AIPS 1:                                    Cal. info for input:
AIPS 1: DOCALIB       1                    > 0 calibrate data & weights
AIPS 1:                                    > 99 do NOT calibrate weights
AIPS 1: GAINUSE       0                    CAL (CL or SN) table to apply
AIPS 1: DOPOL         1                    If >0 correct polarization.
AIPS 1: BLVER        -1                    BL table to apply.
AIPS 1: FLAGVER       0                    Flag table version
AIPS 1: DOBAND       -1                    If >0 apply bandpass cal.
AIPS 1:                                    Method used depends on value
AIPS 1:                                    of DOBAND (see HELP file).
AIPS 1: BPVER         0                    Bandpass table version
AIPS 1: SMOOTH     *all 0                  Smoothing function. See
AIPS 1:                                    HELP SMOOTH for details.
AIPS 1: DPARM         1        *rest 0     Control info:
AIPS 1: DOACOR       -1                    > 0 include autocorrelations
AIPS 1: FACTOR        0                    When DPARM(5)=0 Multiply
AIPS 1:                                    gain listings by FACTOR,
AIPS 1:                                    0=> use scale factor from
AIPS 1:                                    first record printed.
AIPS 1: DOCRT         1                    > 0 -> use the terminal,
AIPS 1:                                    else use the line printer
AIPS 1:                                    > 72 => terminal width
AIPS 1: OUTPRINT   ' '
AIPS 1:                                    Printer disk file to save
AIPS 1: BADDISK    *all 0                  Disk to avoid for scratch.

LISTR OUTPUT:

File = N1569       .DAY1C .   1   Vol = 4  Userid =  333   Chans=     
1 -    1   IF = 1
Freq=  2.207656250 GHz   Ncor=  4   No. vis=      3150
Stokes = FULL Subarray =   1
Applying calibration table   3
Applying polarization corrections
Applying flag table   1


Time =   1/05:20:40 to   1/05:49:40   Source = 3C286           : 0000
Flux = 11.7982 Jy, Calcode =     , Freq =  2.207656250 GHz
Phase, 1000 = 1000.00 degrees, averaging type = Vector
RL in upper right, conjg(LR) in lower left

Ant -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14
   1|      55  55  55  54  55  55  55  55  54  54  55  54  53
   2|  55      55  55  55  55  56  55  54  55  55  55  54  53
   3|  55  55      55  55  56  55  55  55  55  55  55  54  54
   4|  55  55  55      55  55  55  55  55  54  55  55  54  54
   5|  56  55  55  55      55  55  55  55  55  55  55  55  54
   6|  55  55  55  56  55      56  55  55  54  55  55  54  54
   7|  56  55  55  55  55  55      55  55  55  55  55  54  54
   8|  56  55  55  55  55  56  56      55  55  55  55  54  54
   9|  55  55  56  55  55  55  56  55      55  55  55  55  54
  10|  56  55  56  56  55  56  56  56  56      56  55  55  54
  11|  56  56  56  55  55  55  56  56  55  55      56  55  54
  12|  56  55  56  55  55  56  56  55  55  55  55      55  54
  13|  56  55  55  55  55  56  56  55  55  55  55  55      55
  14|  55  55  55  55  55  56  56  56  55  55  55  55  55
Ampscalar average of matrix    = 5.506E+01(2.327E-02) sigma = 3.130E-01
Vector    average of upper data= 5.470E+01            sigma = 1.369E+00
Vector    average of lower data= 5.541E+01            sigma = 1.332E+00

  mazama    LISTR(31DEC07)    333     20-NOV-2007  14:10:18    Page    2
File = N1569       .DAY1C .   1   Vol = 4  Userid =  333   Chans=     
1 -    1   IF = 2
Freq=  2.207656250 GHz   Ncor=  4   No. vis=      3150
Stokes = FULL Subarray =   1
Applying calibration table   3
Applying polarization corrections
Applying flag table   1


Time =   1/05:20:40 to   1/05:49:40   Source = 3C286           : 0000
Flux = 11.7472 Jy, Calcode =     , Freq =  2.225781250 GHz
Phase, 1000 = 1000.00 degrees, averaging type = Vector
RL in upper right, conjg(LR) in lower left

Ant -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14
   1|     104 -13   0   0       0   0   0   0 176 -90 -90 173
   2|   2     -48   0   0    -114-102 -99-105-101-111-113-102
   3|   3 -10     -86 -87    -101 -91 -85 -87 -88 -97 -98 -92
   4|   0   0 -84     -90    -103 -93 -88 -91 -91 -99-101 -94
   5| -90   0-125-163        -128-110-111-126-112-128-131-110
   6|
   7|   0-102 -73-128 -93         -97 -89 -96 -94-111-114 -98
   8|   0-120 -69 137 -99    -124     -93-111 -99-121-127-102
   9|   0-113 -97-136-101    -119-102    -108-101-116-120-103
  10| 139-111 -98-125-101    -117-102 -98    -101-114-117-102
  11| 123-136-133-174-115    -131-111-113-132    -131-135-111
  12|  -8 -98 -77-103 -92    -112 -95 -87 -93 -92    -110 -96
  13| -51-101 -83-110 -94    -113 -97 -90 -97 -94-109     -98
  14| 130 159  51  93 -90    -130 -97 -74 142 -90-131-141
Ampscalar average of matrix    =-9.888E+01(2.248E+00) sigma = 2.923E+01
Vector    average of upper data= 9.159E-02            sigma = 1.587E+01
Vector    average of lower data=-9.007E+01            sigma = 1.213E+01

and so on for IFs 3-8. The R-L phases here are polarization  
calibrated so they should all be more or less the same value, but  
they don't for IFs 2-8.

However, when I do the IFs one at a time (here bif=2;eif=2), the R-L  
phases are consistent with each other, which is what should be  
happening above.

  mazama    LISTR(31DEC07)    333     20-NOV-2007  14:19:18    Page    1
File = N1569       .DAY1C .   1   Vol = 4  Userid =  333   Chans=     
1 -    1   IF =
  2
Freq=  2.207656250 GHz   Ncor=  4   No. vis=      3150
Stokes = FULL Subarray =   1
Applying calibration table   3
Applying polarization corrections
Applying flag table   1


Time =   1/05:20:40 to   1/05:49:40   Source = 3C286           : 0000
Flux = 11.7472 Jy, Calcode =     , Freq =  2.225781250 GHz
Phase, 1000 = 1000.00 degrees, averaging type = Vector
RL in upper right, conjg(LR) in lower left

Ant -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14
   1|    -113-113-112-113    -113-113-113-113-113-113-114-114
   2|-112    -112-113-112    -112-113-113-113-113-113-113-114
   3|-112-112    -112-112    -112-113-113-113-113-113-113-114
   4|-112-112-112    -113    -112-113-112-113-112-113-113-114
   5|-112-112-112-112        -112-112-112-112-112-112-113-113
   6|
   7|-112-112-112-112-112        -113-112-113-113-113-113-113
   8|-112-112-112-112-112    -112    -113-113-112-112-113-113
   9|-112-112-112-112-112    -112-112    -112-112-112-112-113
  10|-111-112-112-112-112    -111-112-112    -112-112-112-113
  11|-111-112-112-112-112    -111-112-112-112    -112-112-112
  12|-112-112-112-112-112    -112-112-112-112-112    -113-113
  13|-111-112-112-112-112    -111-112-112-112-112-112    -112
  14|-112-112-112-112-112    -112-112-112-112-112-112-112
Ampscalar average of matrix    =-1.123E+02(1.654E-02) sigma = 2.059E-01
Vector    average of upper data=-1.127E+02            sigma = 1.527E+00
Vector    average of lower data=-1.119E+02            sigma = 1.519E+00






------------------------------------------------------------------------ 
----------------------------
Amanda Kepley
University of Wisconsin-Madison
Department of Astronomy
Tel: (608) 263-1460
http://www.astro.wisc.edu/~kepley
------------------------------------------------------------------------ 
----------------------------






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