[daip] GMRT data- UVFLP-BLOAT-DBCON

Wed May 14 16:44:34 EDT 2008

gcastell at iafe.uba.ar wrote:
> Dear all,
> 
> I am working on GMRT data at 610 MHz, I am using the 31DEC08 version of AIPS.
> 
> 1) I have two files of 128 channels, for the LSB and USB data.
> 
> 2) I ran splat on the LSB data and also on the USB data. I obtained two
> new files of 7 channels.
> Concerning to SPLAT, I would like to know if the 31DEC08 version of AIPS
> has any problem (I read some emails about bugs in previous
> AIPS version).

SPLAT has not been changed this year.

> Below you can see the header for these files:
> I averaged 16 channels together, after selecting channels from 5 to 116 in
> each sideband
> 
> **USB DATA**
> AIPS 1: Image=MULTI     (UV)         Filename=610_26_A_NEW.SPLAT .   1
> AIPS 1: Telescope=GMRT               Receiver=GMRT
> AIPS 1: Observer=APR                 User #=  338
> AIPS 1: Observ. date=25-FEB-2008     Map date=08-MAY-2008
> AIPS 1: # visibilities    273196     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1:            SOURCE
> 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       1  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         7   6.1250000E+08       1.00 -2.0000000E+06    0.00
> AIPS 1: IF           1   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: RA           1    00 00 00.000       1.00       3600.000    0.00
> AIPS 1: DEC          1    00 00 00.000       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> 
> **LSB DATA*
>> imhe
> AIPS 1: Image=MULTI     (UV)         Filename=610_26_B_NEW.SPLAT .   1
> AIPS 1: Telescope=GMRT               Receiver=GMRT
> AIPS 1: Observer=APR                 User #=  338
> AIPS 1: Observ. date=25-FEB-2008     Map date=09-MAY-2008
> AIPS 1: # visibilities    287112     Sort order  TB
> AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
> AIPS 1:            SOURCE
> 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       1  -1.0000000E+00       1.00 -1.0000000E+00    0.00
> AIPS 1: FREQ         7   6.1550000E+08       1.00  2.0000000E+06    0.00
> AIPS 1: IF           1   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 1: RA           1    00 00 00.000       1.00       3600.000    0.00
> AIPS 1: DEC          1    00 00 00.000       1.00       3600.000    0.00
> AIPS 1: ----------------------------------------------------------------
> 
> 
> 
> 3) After SPLAT, I ran UVFLP on the LSB data to re-ordering the data. Then,
> I ran BLOAT, both on the output of UVFLP and on the output for SPLAT on
> the USB data.
> 
> the inputs for BLOAT were:
> 
> ** LSB DATA **
>  3723  BLOAT RELEASE ='31DEC08 '  /********* Start 13-MAY-2008   12:44:50
>   3724  BLOAT INNAME='G338_610_26B'   INCLASS='UVFLP '
>   3725  BLOAT INSEQ=    1   INDISK=  1
>   3726  BLOAT OUTNAME='G338_610_26B'   OUTCLASS='BLOAT '
>   3727  BLOAT OUTSEQ=    1   OUTDISK=  1
>   3728  BLOAT  APARM(2) =    1 /1ST CHAN. NO. OF INPUT.
>   3729  BLOAT  APARM(1) =   15 /NUMBER OF OUTPUT CHANNELS
>   3730  BLOAT  APARM(3) =    1 / FIRST CHAN. COPIED.
>   3731  BLOAT  APARM(3) =    7 / FIRST CHAN. COPIED.
>   3732  BLOAT /REFERENCE FREQ =       0.61550000E+09
> 
> ** USB DATA**
>  2478  BLOAT RELEASE ='31DEC08 '  /********* Start 13-MAY-2008   12:48:36
>   2479  BLOAT INNAME='G338_610_26A'   INCLASS='UVCOP '
>   2480  BLOAT INSEQ=    1   INDISK=  1
>   2481  BLOAT OUTNAME='G338_610_26A'   OUTCLASS='BLOAT '
>   2482  BLOAT OUTSEQ=    1   OUTDISK=  1
>   2483  BLOAT  APARM(2) =    9 /1ST CHAN. NO. OF INPUT.
>   2484  BLOAT  APARM(1) =   15 /NUMBER OF OUTPUT CHANNELS
>   2485  BLOAT  APARM(3) =    1 / FIRST CHAN. COPIED.
>   2486  BLOAT  APARM(3) =    7 / FIRST CHAN. COPIED.
>   2487  BLOAT /REFERENCE FREQ =       0.61250000E+09
> 
> 5) For DBCON I used the following inputs
> AIPS 1: INNAME     'G338_610_26B'
> AIPS 1: INCLASS    'BLOAT'
> AIPS 1: IN2NAME    'G338_610_26A'
> AIPS 1: IN2CLASS   'BLOAT'
> AIPS 1: REWEIGHT      0           0
> AIPS 1:  DOPOS         1           1        If (1,1) true (+1) check pos.
> AIPS 1:               1           1        will shift second if nec.
> AIPS 1:               1           1        If (2,1) true check freq.
> AIPS 1:               1           0
> AIPS 1: DOARRAY      -1                    If true (+1) output data will
> AIPS 1:                                    be the same subarray as input
> AIPS 1:                                    Forced to +1 for multi-source
> AIPS 1: FQTOL        -1                    > 0 tolerance to not renumber
> AIPS 1:                                      FQs of dataset 2 (in kHz)
> 
> localh> DBCON1: Task DBCON  (release of 31DEC08) begins
> localh> DBCON1: Scaling u,v,w of data set 2 by  1.0261224E+00
> localh> DBCON1: Scaling u,v,w of data set 1 by  1.0194963E+00
> localh> DBCON1: RA and DEC match to within 1 microarcsecond each
> localh> DBCON1: --I'm not going to shift positions
> localh> DBCON1: FREQUENCIES DIFFER BY TOO MUCH:  6.27500000E+08 
> 6.28500000E+08
> localh> DBCON1: MULTI-FREQUENCY DATA BASES INCOMPATABLE
> localh> DBCON1: Purports to die of UNNATURAL causes
> localh> DBCON1: athos        31DEC08 TST: Cpu=       0.0  Real=       0
> 
> 
> I don't know what is wrong. Please, could you help me with my problem???
> I really need your comments!

Well the problem is you have 2 different frequencies, are you sure you want to 
DBCON them?  I.e., treat them as the same frequency?  You can set FQTOL to force 
DBCON to accept the two frequencies as the same.

Amy