[daip] Error with merging VLA and MERLIN data

Eric Greisen egreisen at nrao.edu
Wed Jul 9 11:43:52 EDT 2014


On 07/09/2014 08:14 AM, Doug Gobeille wrote:
> I am encountering an issue when trying to use DBCON to merge two
> datasets: one from the VLA and another from MERLIN. They share similar
> frequencies (C band). My procedure, in short, was as follows:
>
> 1.) Load calibrated data in via FITLD:
>
> restore 0
> indi 1
> outdi 1
> getn 1;zap
> getn 2;zap
> getn 3;zap
> getn 4;zap
> task 'fitld'
> datain 'J0833+1124.MERLIN.010297.C
> go;wait
> datain 'J0833+1124.AS0172.A.C
> go;wait
> getn 1
> imh;wait
> getn 2
> imh;wait
>
> 2.) Adjust phase center of VLA data to coincide with higher resolution
> MERLIN phase center using AXDEFINE:
>
> task 'axdefine'
> naxis 4
> axtype 'ra'
> axref 1
> axinc 0
> axval= 128.30 0.00986666
> axdef
> imh
>
> naxis 5
> axtype 'dec'
> axval= 11.3934 0.0000027778
> axinc 0
> axdef
> imh
>
> 3.) Scaled core fluxes to match using UVMOD:
>
> task 'uvmod'
> factor 1.64125
> go;wait
>
>
> 4.) Attempted to merge new UVMOD file with loaded MERLIN FITS file:
>
> task 'dbcon'
> getn 3
> get2n 1
> dopos 1,-1
> doarray =-1
> go;wait
>
>
> At this point I get the error:
>
> DBCON1: Task DBCON  (release of 31DEC13) begins
> DBCON1: RA does not match, will shift second
> DBCON1: DEC does not match, will shift second
> DBCON1: RA       AXIS HAS UNEQUAL ATTRIBUTES
> DBCON1: Purports to die of UNNATURAL causes
> DBCON1: ubuntu       31DEC13 TST: Cpu=       0.0  Real=       0
> AIPS 1: Resumes
> AIPS 1: DBCON    was not found to be running
>
>
> The entirety of my output is copied below along. The only thing I can
> see is that there are two DEC values at the end rather than one. I
> called imh numerous times throughout to track the progress.
>
> Any thoughts?
>
> ~Doug
>
>
>
> ***************************************OUTPUT******************************************
>
>
>  >task 'fitld'
>  >datain 'J0833+1124.MERLIN.010297.C
>  >go;wait
> FITLD1: Task FITLD  (release of 31DEC13) begins
> FITLD1: Found 0830+115 observed on 01-JAN-1997
> FITLD1: Create 0830+115    .SPLIT .   1 (UV)  on disk  1  cno    1
> AIPS 1: Resumes
> FITLD1: Image=0830+115  (UV)         Filename=0830+115    .SPLIT .   1
> FITLD1: Telescope=MERLIN2            Receiver=
> FITLD1: Observer=                    User #= 3666
> FITLD1: Observ. date=01-JAN-1997     Map date=09-JUL-2014
> FITLD1: # visibilities     13550     Sort order  TB
> FITLD1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> FITLD1: ----------------------------------------------------------------
> FITLD1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> FITLD1: COMPLEX      3   0.0000000E+00       1.00  1.0000000E+00    0.00
> FITLD1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> FITLD1: FREQ         1   4.9940000E+09       1.00  1.3000000E+07    0.00
> FITLD1: IF           1   1.0000000E+00       1.00  1.0000000E+00    0.00
> FITLD1: RA           1    08 33 14.368       1.00       3600.000    0.00
> FITLD1: DEC          1    11 23 36.250       1.00       3600.000    0.00
> FITLD1: ----------------------------------------------------------------
> FITLD1: Coordinate equinox 2000.00
> FITLD1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> FITLD1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> FITLD1: Maximum version number of extension files of type HI is   1
> FITLD1: Maximum version number of extension files of type NX is   1
> FITLD1: Maximum version number of extension files of type FQ is   1
> FITLD1: Maximum version number of extension files of type AN is   1
> FITLD1: Appears to have ended successfully
> FITLD1: ubuntu 31DEC13 TST: Cpu=      0.2  Real=      0  IO=        10
> AIPS 1: Task FITLD   has finished
>  >datain 'J0833+1124.AS0172.A.C
>  >go;wait
> FITLD1: Task FITLD  (release of 31DEC13) begins
> FITLD1: Found AB4      observed on 26-SEP-1983
> FITLD1: Create AB4         .SPLIT .   1 (UV)  on disk  1  cno    2
> FITLD1: UVFDAT: counts for cross-correlations
> FITLD1: UVFDAT: found      26820 spectra samples already flagged
> FITLD1: UVFDAT: found     50.000 percent samples already flagged
> FITLD1: Image=AB4       (UV)         Filename=AB4         .SPLIT .   1
> FITLD1: Telescope=VLA                Receiver=VLA
> FITLD1: Observer=AS172               User #= 3666
> FITLD1: Observ. date=26-SEP-1983     Map date=09-JUL-2014
> FITLD1: # visibilities      6705     Sort order  TB
> FITLD1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> FITLD1: ----------------------------------------------------------------
> FITLD1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> FITLD1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00    0.00
> FITLD1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> FITLD1: FREQ         1   4.8851000E+09       1.00  5.0000000E+07    0.00
> FITLD1: IF           2   1.0000000E+00       1.00  1.0000000E+00    0.00
> LOGFILE FOR USER 3666 GETTING LARGE: USE PRTMSG AND CLRMSG NOW!
> FITLD1: RA           1    08 33 15.041       1.00       3600.000    0.00
> FITLD1: DEC          1    11 23 41.497       1.00       3600.000    0.00
> FITLD1: ----------------------------------------------------------------
> FITLD1: Coordinate equinox 2000.00
> FITLD1: Observed RA   08 30 30.600    DEC  11 33 58.00
> FITLD1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> FITLD1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> FITLD1: Maximum version number of extension files of type HI is   1
> FITLD1: Maximum version number of extension files of type NX is   1
> FITLD1: Maximum version number of extension files of type FQ is   1
> FITLD1: Maximum version number of extension files of type WX is   1
> FITLD1: Maximum version number of extension files of type OF is   1
> FITLD1: Maximum version number of extension files of type AN is   1
> FITLD1: Appears to have ended successfully
> FITLD1: ubuntu 31DEC13 TST: Cpu=      0.0  Real=      0  IO=         2
> AIPS 1: Resumes
> AIPS 1: FITLD    was not found to be running
>  >getn 1
> AIPS 1: Got(1)   disk= 1  user=3666   type=UV   0830+115.SPLIT.1
>  >imh;wait
> AIPS 1: Image=0830+115  (UV)         Filename=0830+115    .SPLIT .   1
> AIPS 1: Telescope=MERLIN2            Receiver=
> AIPS 1: Observer=                    User #= 3666
> AIPS 1: Observ. date=01-JAN-1997     Map date=09-JUL-2014
> AIPS 1: # visibilities     13550     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> AIPS 1: COMPLEX      3   0.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         1   4.9940000E+09       1.00  1.3000000E+07    0.00
> AIPS 1: IF           1   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: RA           1    08 33 14.368       1.00       3600.000    0.00
> AIPS 1: DEC          1    11 23 36.250       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Coordinate equinox 2000.00
> AIPS 1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> AIPS 1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> AIPS 1: Maximum version number of extension files of type HI is   1
> AIPS 1: Maximum version number of extension files of type NX is   1
> AIPS 1: Maximum version number of extension files of type FQ is   1
> AIPS 1: Maximum version number of extension files of type AN is   1
> AIPS 1: FITLD    was not found to be running
>  >getn 2
> AIPS 1: Got(1)   disk= 1  user=3666   type=UV   AB4.SPLIT.1
>  >imh;wait
> AIPS 1: Image=AB4       (UV)         Filename=AB4         .SPLIT .   1
> AIPS 1: Telescope=VLA                Receiver=VLA
> AIPS 1: Observer=AS172               User #= 3666
> AIPS 1: Observ. date=26-SEP-1983     Map date=09-JUL-2014
> AIPS 1: # visibilities      6705     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> AIPS 1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         1   4.8851000E+09       1.00  5.0000000E+07    0.00
> AIPS 1: IF           2   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: RA           1    08 33 15.041       1.00       3600.000    0.00
> AIPS 1: DEC          1    11 23 41.497       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Coordinate equinox 2000.00
> AIPS 1: Observed RA   08 30 30.600    DEC  11 33 58.00
> AIPS 1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> AIPS 1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> AIPS 1: Maximum version number of extension files of type HI is   1
> AIPS 1: Maximum version number of extension files of type NX is   1
> AIPS 1: Maximum version number of extension files of type FQ is   1
> AIPS 1: Maximum version number of extension files of type WX is   1
> AIPS 1: Maximum version number of extension files of type OF is   1
> AIPS 1: Maximum version number of extension files of type AN is   1
> AIPS 1: Keyword = 'CORRMODE'  value = '        '
> AIPS 1: Keyword = 'VLAIFS  '  value = 'ABCD    '
> AIPS 1: Keyword = 'CORRCOEF'  value =           -1
> AIPS 1: Keyword = 'MAXABSU '  value = -1.000000E+00
> AIPS 1: Keyword = 'SOURNAM1'  value = 'AB4     '
> AIPS 1: Keyword = 'SOURNAM2'  value = '        '
> AIPS 1: FITLD    was not found to be running
>  >
>  >
>  >task 'axdefine'
>  >naxis 4
>  >axtype 'ra'
>  >axref 1
>  >axinc 0
>  >axval= 128.30 0.00986666
>  >axdef
>  >imh
> AIPS 1: Image=AB4       (UV)         Filename=AB4         .SPLIT .   1
> AIPS 1: Telescope=VLA                Receiver=VLA
> AIPS 1: Observer=AS172               User #= 3666
> AIPS 1: Observ. date=26-SEP-1983     Map date=09-JUL-2014
> AIPS 1: # visibilities      6705     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> AIPS 1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         1   4.8851000E+09       1.00  5.0000000E+07    0.00
> AIPS 1: RA           2    08 33 14.369       1.00       3600.000    0.00
> AIPS 1: RA           1    08 33 15.041       1.00       3600.000    0.00
> AIPS 1: DEC          1    11 23 41.497       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Coordinate equinox 2000.00
> AIPS 1: Observed RA   08 30 30.600    DEC  11 33 58.00
> AIPS 1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> AIPS 1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> AIPS 1: Maximum version number of extension files of type HI is   1
> AIPS 1: Maximum version number of extension files of type NX is   1
> AIPS 1: Maximum version number of extension files of type FQ is   1
> AIPS 1: Maximum version number of extension files of type WX is   1
> AIPS 1: Maximum version number of extension files of type OF is   1
> AIPS 1: Maximum version number of extension files of type AN is   1
> AIPS 1: Keyword = 'CORRMODE'  value = '        '
> AIPS 1: Keyword = 'VLAIFS  '  value = 'ABCD    '
> AIPS 1: Keyword = 'CORRCOEF'  value =           -1
> AIPS 1: Keyword = 'MAXABSU '  value = -1.000000E+00
> AIPS 1: Keyword = 'SOURNAM1'  value = 'AB4     '
> AIPS 1: Keyword = 'SOURNAM2'  value = '        '
>  >
>  >naxis 5
>  >axtype 'dec'
>  >axval= 11.3934 0.0000027778
>  >axinc 0
>  >axdef
>  >imh
> AIPS 1: Image=AB4       (UV)         Filename=AB4         .SPLIT .   1
> AIPS 1: Telescope=VLA                Receiver=VLA
> AIPS 1: Observer=AS172               User #= 3666
> AIPS 1: Observ. date=26-SEP-1983     Map date=09-JUL-2014
> AIPS 1: # visibilities      6705     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> AIPS 1: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         1   4.8851000E+09       1.00  5.0000000E+07    0.00
> AIPS 1: RA           2    08 33 14.369       1.00       3600.000    0.00
> AIPS 1: DEC          1    11 23 36.251       1.00       3600.000    0.00
> AIPS 1: DEC          1    11 23 41.497       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> AIPS 1: Coordinate equinox 2000.00
> AIPS 1: Observed RA   08 30 30.600    DEC  11 33 58.00
> AIPS 1: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> AIPS 1: Alt ref. value  0.00000E+00  wrt pixel    1.00
> AIPS 1: Maximum version number of extension files of type HI is   1
> AIPS 1: Maximum version number of extension files of type NX is   1
> AIPS 1: Maximum version number of extension files of type FQ is   1
> AIPS 1: Maximum version number of extension files of type WX is   1
> AIPS 1: Maximum version number of extension files of type OF is   1
> AIPS 1: Maximum version number of extension files of type AN is   1
> AIPS 1: Keyword = 'CORRMODE'  value = '        '
> AIPS 1: Keyword = 'VLAIFS  '  value = 'ABCD    '
> AIPS 1: Keyword = 'CORRCOEF'  value =           -1
> AIPS 1: Keyword = 'MAXABSU '  value = -1.000000E+00
> AIPS 1: Keyword = 'SOURNAM1'  value = 'AB4     '
> AIPS 1: Keyword = 'SOURNAM2'  value = '        '
>  >
>  >task 'uvmod'
>  >factor 1.64125
>  >go;wait
> UVMOD1: Task UVMOD  (release of 31DEC13) begins
> UVMOD1: UVGET: doing no flagging this time
> UVMOD1: Create AB4         .UVMOD .   1 (UV)  on disk  1  cno    3
> UVMOD1: UVMOD TYPE( 001) = 'POIN'
> UVMOD1: UVMOD IMAX( 001) =   0.0000E+00 / in Jy.
> UVMOD1: UVMOD QMAX( 001) =   0.0000E+00 / in Jy.
> UVMOD1: UVMOD UMAX( 001) =   0.0000E+00 / in Jy.
> UVMOD1: UVMOD VMAX( 001) =   0.0000E+00 / in Jy.
> UVMOD1: UVMOD GPOS(1, 001) =   0.0000E+00 / in Arcsec.
> UVMOD1: UVMOD GPOS(2, 001) =   0.0000E+00 / in Arcsec.
> UVMOD1: UVMOD FLUX =   0.0000E+00 / noise added in Jy./Wgt.
> UVMOD1: UVMOD FACTOR =   1.6413E+00
> UVMOD1: Copied OF file from vol/cno/vers  1    2   1 to  1    3   1
> UVMOD1: Updating tables for IF/FREQID/channel selection
> UVMOD1: Reformatted AN file from vol/cno/vers  1    2   1 to  1    3   1
> UVMOD1: Copied WX file from vol/cno/vers  1    2   1 to  1    3   1
> UVMOD1: Appears to have ended successfully
> UVMOD1: ubuntu 31DEC13 TST: Cpu=      0.0  Real=      0  IO=         3
> AIPS 1: Resumes
> AIPS 1: UVMOD    was not found to be running
>  >
>  >task 'dbcon'
>  >getn 3
> AIPS 1: Got(1)   disk= 1  user=3666   type=UV   AB4.UVMOD.1
>  >get2n 1
> AIPS 1: Got(2)   disk= 1  user=3666   type=UV   0830+115.SPLIT.1
>  >dopos 1,-1
>  >doarray =-1
>  >go;wait
> DBCON1: Task DBCON  (release of 31DEC13) begins
> DBCON1: RA does not match, will shift second
> DBCON1: DEC does not match, will shift second
> DBCON1: RA       AXIS HAS UNEQUAL ATTRIBUTES
> DBCON1: Purports to die of UNNATURAL causes
> DBCON1: ubuntu       31DEC13 TST: Cpu=       0.0  Real=       0
> AIPS 1: Resumes
> AIPS 1: DBCON    was not found to be running

1. Your biggest problem here is that you have 2 IFs in the VLA data set.
You will need to run UVCOP with BIF=EIF=1 and then with BIF=EIF=2 make 2 
separate files.  Then concatanate the 3 in 2 separate runs of DBCON.

2. It is fortunate that you did not do AXDEFINE correctly.  Axis 4 is IF 
not RA/DEC which are axes 5 and 6.  But you CANNOT "shift" a coordinate 
of a data set by a header change, you must actually change all observed 
phases and this change is plenty big enough to matter.
DBCON will do this (if you let it) so there is not need to do anything else.

Eric Greisen





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