[daip] FRING in TST, bug fix 13398 has no effect

[Eric Greisen]

Thomas Krichbaum wrote:
> Hi
> 
> I did some more test using FRING in version 'new' and 'tst' using ap9=1.
> 
> The SN-tables produced by both versions are identical. The bug fix
> mentioned in CHANGE.DOC (13398.  January 21, 2011) seems to
> have no affect in our TST version (31DEC11). 
> 
> Can you please check, if the correct version of FRING is implemented under TST.
> 

The bug fix mentioned in 13398 is mentioned in that number in both TST 
and NEW - a patch was performed for this bug, so the two versions should 
be the same.  It appears that there are additional difficulties.  If you 
wish to compare versions use OLD in Bonn at least in this case.

I will take a look at this code again but I am quite sure that the 
January fix is in place.

Eric Greisen


> best regards 
>                               Thomas
> 
> 
> here a more extreme example:
> 
>   1    2   14-SEP-2011  20:26:37     FRING     Time=   0/ 19 05 29, Polarization = 2
> 
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(01): Phas=****** rate=      6.69 delay=    347.87 SNR=  10.3
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(02): Phas=****** rate=    -42.26 delay=    196.57 SNR=   7.8
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(03): Phas=****** rate=    -24.21 delay=    367.99 SNR=  10.7
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(04): Phas=3271.6 rate=    -75.26 delay=   -211.49 SNR=  12.0
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(06): Phas=****** rate=   -112.27 delay=    312.61 SNR=   9.6
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(07): Phas=****** rate=    -26.83 delay=    342.43 SNR=   6.4
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(08): Phas=-670.8 rate=    -24.45 delay=    146.65 SNR=   9.2
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(09): Phas=****** rate=    -33.23 delay=    134.15 SNR=   7.7
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(10): Phas=-720.6 rate=     -5.82 delay=    295.55 SNR=   8.1
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(11): Phas=****** rate=    -24.56 delay=    190.89 SNR=   7.8
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(12): Phas=****** rate=     -2.80 delay=    311.55 SNR=  10.4
>    1    3   14-SEP-2011  20:26:59     FRING     Ant(13): Phas=-342.8 rate=    -40.83 delay=    189.65 SNR=   7.8
> 
> 
> 
> 
> 
> ----------  Forwarded Message  ----------
> 
> Subject: Fringe, exhaustive baseline search gives wrong solution
> Date: Wednesday 14 September 2011
> From: Thomas Krichbaum <tkrichbaum at mpifr-bonn.mpg.de>
> To: "aips, daip" <daip at nrao.edu>
> 
> Hi,
> 
> I use FRING in version 'new' and 'tst'. I run it in the exhaustive baseline search mode using ap5=1 and ap7=1. 
> This is necessary since the data have low SNR (3mm-VLBI). 
> 
> The parms are set like this:
> REFANT        5   
> SEARCH       12   11 3 4 13 2 0
> SOLINT          4
> SOLSUB        2
> SOLMIN         1
> APARM 2 0 0 0 1 2 4 0 1 0 
> DPARM 2 500 500 1 0 0 1 0
> 
> As in some earlier versions, I again encounter 'wrong' solutions, which appear occassionally.
> I thought that bug was fixed some time ago. 
> 
> In the coarse search I see phases above 360 deg or even with "****". 
> 
> The POSSM plot shows that the delays on some baselines come out wrongly. 
> 
> When I switch off exhaustive mode (set aparm9=0) the effect seems to dissappear. However
> that mode gives too few solutions, since FRINGE does not cycle through the full antenna list.
> 
> Here the prtmsg output for a particular scan:
> 
>    1    3   14-SEP-2011  19:12:29     FRING     IF number =    1 Poln. =   1
>    1    3   14-SEP-2011  19:12:29     FRING     Fitted phases, rates, delays and SNR: [ P = phase(deg),
>    1    3   14-SEP-2011  19:12:29     FRING       R = rate(mHz), D = Single-Band Delay(nsec), S = SNR ]
>    1    3   14-SEP-2011  19:12:29     FRING       R = rate(mHz), D = Single-Band Delay(nsec), S = SNR ]
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(01): Phas=-959.6 rate=     -1.81 delay=      2.86 SNR=  20.4
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(03): Phas=****** rate=     27.16 delay=    -11.47 SNR=  21.6
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(04): Phas=****** rate=      0.74 delay=      3.06 SNR=  21.4
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(07): Phas=****** rate=     17.50 delay=      2.02 SNR=  20.2
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(08): Phas=-958.2 rate=    -24.19 delay=     -0.23 SNR=  18.6
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(10): Phas=****** rate=     -2.38 delay=      1.83 SNR=  21.5
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(11): Phas=****** rate=      2.69 delay=      2.66 SNR=  22.1
>    1    3   14-SEP-2011  19:12:29     FRING     Ant(12): Phas=****** rate=     -4.39 delay=      3.46 SNR=  22.1
>    1    3   14-SEP-2011  19:12:29     FRING     Standard RMS errors (deg, mHz, nsec):
> 
> 
> Is this a bug ?
> 
> 
> best regards, Thomas
> 
>  
>