[daip] return of a CALIB failure (31DEC04 AIPS)

Daniel Lebach dlebach at cfa.harvard.edu
Mon Nov 22 21:45:55 EST 2004


Hi Eric,

In June I wrote the daip (= you?) about a CALIB problem I had that
appeared after you NRAO folks made modifications to the code.  You
very promptly replied, identified the problem, and fixed it.
Unfortunately, the identical problem has returned.  Below is a copy
of my emails to you back then.

Would it be easy for you to correct the problem again?

The version of CALIB I now run (31DEC04 AIPS under Linux w/
"midnight job" updates) DOES include the message:

CALIB5: WARNING: PURE BASELINE RATHER THAN ONLY ANTENNA SOLUTIONS ALLOWE
        D

Best regards,
Dan


> To: daip at nrao.edu
> Subject: CALIB failure (31DEC03 AIPS on DEC ALPHA) w/ basic settings
> Cc: biet, ryan
> From: Daniel Lebach <dlebach at cfa.harvard.edu>
> Date: Wed Jun  9 15:49:59 2004
> 
> 
> Hello,
> 
> I have been running CALIB for years w/o troubles, but now I can't
> seem to get anything out but an SN table of null solutions (i.e., all
> phases are 'INDE' and all delays and rates are 0.0).  My troubles are
> with 31DEC03 AIPS and I think the latest 31DEC04 AIPS on our system.
> I am running AIPS on a DEC ALPHA.  Perhaps I just have some incorrect
> adverb setting, but if so, I can't find it.  My troubles exist for
> multiple UV data sets, including at least one for which I ran CALIB
> successfully with (I think) the same adverb settings under 31DEC03
> AIPS about a year ago.  I have tried changing numerous adverb
> settings w/o success.  Here are my default settings (31DEC03 AIPS):
> 
> >inp
> AIPS 1: CALIB:  Task to determine calibration for data.
> AIPS 1: Adverbs     Values                 Comments
> AIPS 1: ----------------------------------------------------------------
> AIPS 1:                                    Input uv data.
> AIPS 1: INNAME     'BR080B      '             UV file name (name)
> AIPS 1: INCLASS    'UVCOP '                   UV file name (class)
> AIPS 1: INSEQ         2                       UV file name (seq. #)
> AIPS 1: INDISK        5                       UV file disk drive #
> AIPS 1:                                    Data selection (multisource):
> AIPS 1: CALSOUR    'HR8703          '      Calibrator sources
> AIPS 1:            *rest ' '
> AIPS 1: QUAL         -1                    Calibrator qualifier -1=>all
> AIPS 1: CALCODE    '    '                  Calibrator code '    '=>all
> 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: TIMERANG   *all 0                  Time range to use.
> AIPS 1: BCHAN         0                    Lowest channel number 0=>all
> AIPS 1: ECHAN        16                    Highest channel number
> AIPS 1: ANTENNAS      1           2        Antennas to select. 0=all
> AIPS 1:            *rest 0
> AIPS 1: ** press RETURN for more, enter Q or next line to quit print **
> #
> AIPS 1: DOFIT      *all 0                  Subset of ANTENNAS list for
> AIPS 1:                                    which solns are desired.  0
> AIPS 1:                                    => all in ANTENNAS, < 0 all
> AIPS 1:                                    but those in DOFIT
> AIPS 1: ANTUSE     *all 0                  Mean gain is calculated
> AIPS 1:                                    (CPARM(2)>0) using only the
> AIPS 1:                                    listed antennas. See explain.
> AIPS 1: SUBARRAY      0                    Subarray, 0=>all
> AIPS 1: UVRANGE       0           0        Range of uv distance for full
> AIPS 1:                                    weight
> AIPS 1: WTUV          0                    Weight outside UVRANGE 0=0.
> AIPS 1:
> AIPS 1:                                    Cal. info for input:
> AIPS 1: DOCALIB       1                    If >0 calibrate data
> AIPS 1:                                    = 2 calibrate weights
> AIPS 1: GAINUSE       9                    CL table to apply.
> AIPS 1: DOPOL        -1                    If >0 correct polarization.
> AIPS 1: BLVER        -1                    BL table to apply.
> AIPS 1: FLAGVER       1                    Flag table version
> AIPS 1: DOBAND        1                    If >0 apply bandpass cal.
> AIPS 1:                                    Method used depends on value
> AIPS 1: ** press RETURN for more, enter Q or next line to quit print **
> #
> AIPS 1:                                    of DOBAND (see HELP file).
> AIPS 1: BPVER         1                    Bandpass table version
> AIPS 1: SMOOTH     *all 0                  Smoothing function. See
> AIPS 1:                                    HELP SMOOTH for details.
> AIPS 1:
> AIPS 1:                                    CLEAN map. See HELP.
> AIPS 1: IN2NAME    '            '             Cleaned map name (name)
> AIPS 1: IN2CLASS   '      '                   Cleaned map name (class)
> AIPS 1: IN2SEQ        0                       Cleaned map name (seq. #)
> AIPS 1: IN2DISK       0                       Cleaned map disk unit #
> AIPS 1: INVERS        0                    CC file version #.
> AIPS 1: NCOMP      *all 0                  # comps to use for model.
> AIPS 1:                                    1 value per field
> AIPS 1: FLUX          0                    Lowest CC component used.
> AIPS 1: NMAPS         0                    No. Clean map files
> AIPS 1: CMETHOD    'DFT '                  Modeling method:
> AIPS 1:                                    'DFT','GRID','    '
> AIPS 1: CMODEL     '    '                  Model type: 'COMP','IMAG'
> AIPS 1: SMODEL     *all 0                  Source model, 1=flux,2=x,3=y
> AIPS 1:                                    See HELP SMODEL for models.
> AIPS 1:
> AIPS 1: ** press RETURN for more, enter Q or next line to quit print **
> #
> AIPS 1:                                    Output uv data file.
> AIPS 1: OUTNAME    '            '             UV file name (name)
> AIPS 1: OUTCLASS   '      '                   UV file name (class)
> AIPS 1: OUTSEQ        0                       UV file name (seq. #)
> AIPS 1: OUTDISK       0                       UV file disk drive #
> AIPS 1:
> AIPS 1:                                    Solution control adverbs:
> AIPS 1: REFANT        1                    Reference antenna
> AIPS 1: SOLINT        0                    Solution interval (min)
> AIPS 1: APARM         2           0        General parameters
> AIPS 1:               0           0           1=min. no. antennas
> AIPS 1:               1           0           2 > 0 => data divided
> AIPS 1:              0.01      *rest 0        3 > 0 => avg. RR,LL
> AIPS 1:                                       5 > 0 => avg. IFs.
> AIPS 1:                                       6=print level, 1=good,
> AIPS 1:                                         2 closure, 3 SNR
> AIPS 1:                                       7=SNR cutoff (0=>5)
> AIPS 1:                                       8=max. ant. # (no AN)
> AIPS 1:                                       9 > 0 => pass failed soln
> AIPS 1:                                    Phase-amplitude Parameters:
> AIPS 1: SOLTYPE    '    '                  Soln type,'  ','L1','GCON'
> AIPS 1: ** press RETURN for more, enter Q or next line to quit print **
> #
> AIPS 1: SOLMODE    'P   '                  Soln. mode: 'A&P','P','P!A',
> AIPS 1:                                    'GCON'
> AIPS 1: SOLCON        0                    Gain constraint factor.
> AIPS 1: MINAMPER      0                    Amplitude closure error
> AIPS 1:                                    regarded as excessive in %
> AIPS 1: MINPHSER      0                    Phase closure error regarded
> AIPS 1:                                    as excessive in degrees
> AIPS 1: CPARM      *all 0                  Phase-amp. parameters
> AIPS 1:                                       1 = Min el for gain
> AIPS 1:                                            normalization (deg)
> AIPS 1:                                       2 >0 => normalize gain
> AIPS 1:                                       3 avg. amp. closure err
> AIPS 1:                                       4 avg. ph. closure err
> AIPS 1:                                       5 >0 => scalar average
> AIPS 1:
> AIPS 1: SNVER         9                    Output SN table, 0=>new table
> AIPS 1: ANTWT      *all 0                  Ant. weights (0=>1.0)
> AIPS 1: GAINERR    *all 0                  Std. Dev. of antenna gains.
> AIPS 1: BADDISK       0           0        Disk no. not to use for
> AIPS 1:               1           2           scratch files.
> AIPS 1:            *rest 0
> >
> > go calib
> CALIB1: Task CALIB  (release of 31DEC03) begins
> CALIB1: CALIB USING BR080B       . UVCOP  .   2 DISK=  5 USID=2101
> CALIB1: Selecting, editing and calibrating the data
> CALIB1: Doing cal transfer mode with point model for each source
> CALIB1: This is not self-calibration
> CALIB1: Dividing data by source flux densities
> CALIB1: Determining solutions
> CALIB1: Writing SN table    9
> CALIB1: Found          246 good solutions
> CALIB1: Failed on      287 solutions
> CALIB1:                123 solutions had insufficient data
> CALIB1: Appears to have ended successfully
> CALIB1: rgalp7 31DEC03 NEW: Cpu=     6.1  Real=   125  IO=    206303
> AIPS 1: Resumes
> 
> In all test cases the number of reported failed solutions is a bit
> greater than the number of good solutions.  In principle there should
> be few if any failed solutions.  Despite the fact that good solutions
> do exist, the entire output SN table is null (as described above).
> 
> Can anybody tell me what's going on?  Again, as best as I can tell,
> my adverb settings are identical to those I used for a successful run
> of CALIB on this exact data set last year.
> 
> Thanks,
> Dan Lebach
> 
> 
> To: egreisen at nrao.edu
> Subject: Re: [daip] CALIB failure (31DEC03 AIPS on DEC ALPHA) w/ basic settings
> Cc: daip at nrao.edu, michael at polaris.phys.yorku.ca, ransom at polaris.phys.yorku.ca
> From: Daniel Lebach <dlebach at cfa.harvard.edu>
> 
> 
> Hi Eric,
> 
> Thanks for your prompt reply.
> > 
> > If you ask for only 2 antennas then you cannot get antenna-based
> > solutions.  At least 4 antennas must be used.
> > 
> Is this a new feature?  I set APARM(1) = 2 (just as I always have).
> I prefer to get solutions one baseline at a time to get phases that
> include structure effects (note that I use no structure model).  If I
> use more than 2 antennas then I am necessarily imposing closure
> constraints, and I don't want that.  Note that the baseline-based
> phases I get are exported out of AIPS (after the model phases are
> added so that total phases are exported) for further analysis with
> software designed to handle baseline data.  All I want from CALIB are
> best-fit phase corrections to the phases in the input CL table
> (SOLMODE 'P').  CALIB used to provide these for me just fine until
> now.  Did CALIB change?  If so, can you provide me the source code
> for the 31DEC02 version of CALIB?  I no longer have access to that.
> (That old source code is useful only if I can embed it into
> 31DEC03 AIPS.)
> 
> Dan
> 
> To: egreisen at nrao.edu
> Cc: biet
> Subject: Re: [daip] CALIB failure (31DEC03 AIPS on DEC ALPHA) w/ basic settings
> From: Daniel Lebach <dlebach at cfa.harvard.edu>
> 
> 
> In response to:
> 
> > 
> > CALIB was always intended to do antenna based solutions, never to be
> > perverted in the fashion you are doing.  Nonetheless, the change to
> > prohibit your mode was made inadvertantly when fixing the code to
> > make a better default for small arrays.  I will change 31DEC04 back
> > but add a warning message to users who do not know what they are doing
> > - unlike you most of them will not understand what a two antenna
> > solution actually does.
> > 
> Great!  Thank you!  Your changes are very much appreciated.
> 
> Dan
> 
> P.S. I've long held the view that one of the redeeming qualities of
> AIPS is precisely its versatility, i.e., that existing AIPS tasks can
> be used to perform useful operations that the creators of those tasks
> never dreamed of.  I recognize that my particular application of
> CALIB is a bit strange, but nevertheless, it is very useful to me.
> Thanks again.
> 




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