[daip] possible problem with FRING ?

Miller Goss mgoss at aoc.nrao.edu
Sun Dec 15 13:18:46 EST 2002


I can really imagine that the following is a USER error . If so my 
apologies.

I run FRING on this single source data set with 128 channels.


AIPS 2: Image=W75N      (UV)         Filename=W75N        .SP-67 .   1
AIPS 2: # visibilities    109486     Sort order  TB
AIPS 2: --------------------------------------------------------------
AIPS 2: Type    Pixels   Coord value  at Pixel    Coord incr   Rotat
AIPS 2: COMPLEX      1    1.000000E+00       1    1.0000E+00    0.00
AIPS 2: STOKES       4    RR                 1       -1.0000    0.00
AIPS 2: FREQ       128    1.667240E+09       1    9.7656E+02    0.00
AIPS 2: IF           1    1.000000E+00       1    1.0000E+00    0.00
AIPS 2: RA           1    20 38 36.390       1      3600.000    0.00
AIPS 2: DEC          1    42 37 34.300       1      3600.000    0.00
AIPS 2: --------------------------------------------------------------
AIPS 2: Max ext file #: FQ   1    HI   1    AN   1    OB   1    WX   1
AIPS 2: Max ext file #: SN   1
>

I pick a fixed channel ( ch 69 ) and fring is quite happy .
: You are using a non-standard program
FRING2: Create W75N        .FRING .   1 (UV)  on disk  1  cno  113
FRING2: Selecting the data
AIPS 2: Resumes
>FRING2: VISDFT: Begin DFT component division
FRING2: VISDFT: Model components of type Point
FRING2: Model computation is    10 percent complete
FRING2: Model computation is    20 percent complete
FRING2: Model computation is    30 percent complete
FRING2: Model computation is    40 percent complete
FRING2: Model computation is    50 percent complete
FRING2: Model computation is    60 percent complete
FRING2: Model computation is    70 percent complete
FRING2: Model computation is    80 percent complete
FRING2: Model computation is    90 percent complete
FRING2: Model computation is   100 percent complete
FRING2: Field    1 used       0 CCs
FRING2: Determining solutions
FRING2: Writing SN table    1
FRING2: FIT DID NOT CONVERGE FOR IF    1
FRING2:  This probably means that the starting value for the
FRING2:  delay or rate for one or more antennae is bad.  You
FRING2:  may want to set search windows and try again.
FRING2: Found     3788 good solutions
FRING2: Failed on       14 solutions
FRING2: Adjusting soG2: Applying solutions to data
FRING2: ** WARNING - Subarray   1 contains VLBA data, but no CQ data
FRING2: ** to enable VLBA decorrelation corrections
FRING2: ** Type EXPLAIN FITLD for further information
FRING2:            Previously flagged   Flagged by gain         Kept
FRING2: Partially                    9                   0         9
FRING2: Fully                        0                   0    109477
FRING2: Copied AN file from vol/cno/vers  1   91   1 to  1  113   1
FRING2: Copied OB file from vol/cno/vers  1   91   1 to  1  113   1
FRING2: Copied WX file from vol/cno/vers  1   91   1 to  1  113   1
FRING2: Appears to have ended successfully
FRING2: par


The sn table is there on the input multi source data base with
128 channels and looks ok . ie the phases and rates are ok .


The output uv single source is




AIPS 2: Image=W75N      (UV)         Filename=W75N        .FRING .   1
AIPS 2: # visibilities    109486     Sort order  TB
AIPS 2: --------------------------------------------------------------
AIPS 2: Type    Pixels   Coord value  at Pixel    Coord incr   Rotat
AIPS 2: COMPLEX      1    1.000000E+00       1    1.0000E+00    0.00
AIPS 2: STOKES       4    RR                 1       -1.0000    0.00
AIPS 2: FREQ         1    1.667240E+09       1    9.7656E+02    0.00
AIPS 2: IF           1    1.000000E+00       1    1.0000E+00    0.00
AIPS 2: RA           1    20 38 36.390       1      3600.000    0.00
AIPS 2: DEC          1    42 37 34.300       1      3600.000    0.00
AIPS 2: --------------------------------------------------------------
AIPS 2: Max ext file #: FQ   1    HI   1    AN   1    OB   1    WX   1
>


and has a single channel . I was not certain if this would produce 
a single channel or 128 channels.

Then I try to uvplt this latter ( W75N.FRING.1 )
and get np
AIPS 2: UVPLT     Plots data from a u,v data base: multi-channel version
AIPS 2: Adverbs     Values                 Comments
AIPS 2: ----------------------------------------------------------------
AIPS 2: USERID        0                    Data base owner number
AIPS 2: INNAME     'W75N        '          Input UV file name (name)
AIPS 2: INCLASS    'FRING '                Input UV file name (class)
AIPS 2: INSEQ         1                    Input UV file name (seq. #)
AIPS 2: INDISK        1                    Input UV file disk unit #
AIPS 2: SOURCES    'W75N            '      Sources to plot, ' '=>all.
AIPS 2:            *rest ' '
AIPS 2: QUAL         -1                    Qualifier -1=>all
AIPS 2: CALCODE    '    '                  Calibrator code '    '=>all
AIPS 2: STOKES     '    '                  Stokes type to select.
AIPS 2: SELBAND      -1                    Bandwidth to select (kHz)
AIPS 2: SELFREQ      -1                    Frequency to select (MHz)
AIPS 2: FREQID       -1                    Freq. ID to select.
AIPS 2: TIMERANG   *all 0                  Time range to select
AIPS 2: ANTENNAS   *all 0                  Antennas to plot
AIPS 2: BASELINE   *all 0                  Baselines with ANTENNAS
AIPS 2: UVRANGE       0           0        UV range in kilolambda.
AIPS 2: SUBARRAY      0                    Subarray, 0 => all
AIPS 2: BCHAN         0                    1st spectral channel #
AIPS 2: ECHAN         0                    Last spectral channel #
AIPS 2: ** press RETURN for more, enter Q or next line to quit print **
#stokes 'rr'
>go
UVPLT2: Task UVPLT  (release of 31DEC02) begins
UVPLT2: XYSCAL: AXIS 2 DEGENERATE
UVPLT2: SCAL: XYSCL ERROR  1
UVPLT2: Purports to die of UNNATURAL causes
UVPLT2: parkes       31DEC02 TST: Cpu=       0.2  Real=       1
AIPS 2: Resumes
>stokes ''
>go
UVPLT2: Task UVPLT  (release of 31DEC02) begins
UVPLT2: XYSCAL: AXIS 2 DEGENERATE
UVPLT2: SCAL: XYSCL ERROR  1
UVPLT2: Purports to die of UNNATURAL causes
UVPLT2: parkes       31DEC02 TST: Cpu=       0.2  Real=       0
AIPS 2: Resumes
>



This does not look good :



e = W75N        .FRING .   1   Vol = 1    Userid =  321     Channels =    
1 to     1
Source= W75N       RA   =  20 38 36.39   DEC  =  42 37 34.3 IF =  1
Freq=  1.667239953 GHz   Ncor=  4   No. vis=    109486   Sort order= TB
Weights have been multiplied by  1.0E-12

W75N      1.667239953 TB      1 RR          1 LL          1 RL          1 
LR
 Vis #     IAT      Ant    Amp Phas Wt   Amp Phas Wt   Amp Phas Wt   Amp 
Phas Wt

     1  0/18:46:21  3- 9*******  90 94*******   3 94*******   0 94*******  
90 94
     2  0/18:46:21  3- 7*******  90 94*******   3 94*******   0 94*******  
90 94
     3  0/18:46:21  1- 3*******  90 94*******   3 94*******   0 94*******  
90 94
     4  0/18:46:21  2- 3*******  90 94*******   3 94*******   0 94*******  
90 94
     5  0/18:46:21  3- 5*******  90 94*******   3 94*******   0 94*******  
90 94
     6  0/18:46:21  7- 9*******  90 94*******   3 94*******   0 94*******  
90 94
     7  0/18:46:21  1- 9*******  90 94*******   3 94*******   0 94*******  
90 94
     8  0/18:46:21  2- 9*******  90 94*******   3 94*******   0 94*******  
90 94
     9  0/18:46:21  5- 9*******  90 94*******   3 94*******   0 94*******  
90 94
    10  0/18:46:21  1- 7*******  90 94*******   3 94*******   0 94*******  
90 94
    11  0/18:46:21  2- 7*******  90 94*******   3 94*******   0 94*******  
90 94
    12  0/18:46:21  5- 7*******  90 94*******   3 94*******   0 94*******  
90 94
    13  0/18:46:21  1- 2*******  90 94*******   3 94*******   0 94*******  
90 94
    14  0/18:46:21  1- 5*******  90 94*******   3 94*******   0 94*******  
90 94
    15  0/18:46:21  2- 5*******  90 94*******   3 94*******   0 94*******  
90 94
Type Q to stop, just hit RETURN to continue



When I then split the original data W75N67 with the sn
table and uvplt it and imagr it , the data is fine.

thanks
miller





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