[daip] Your query of the analysts

Hau Yu Liu hyliu at asiaa.sinica.edu.tw
Mon Oct 20 20:37:35 EDT 2008


Dear sir,

  Currently I met a problem of using AIPS to load VLA archived data AK0517.
I used the task fillm to do it, and leaves most of the options blank, as listed:

#task 'fillm'
>inp
AIPS 1: FILLM     Task to read a VLA archive tape
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: INTAPE        1                    Tape drive number
AIPS 1: INFILE     'AK517:AK517_'          Non-blank: disk file name
AIPS 1: NFILES        0                    Number of files to advance
AIPS 1:                                    Also applies to ON-LINE!
AIPS 1: BAND       ' '                     Freq. band:
AIPS 1:                                      (4,P,L,S,C,X,U,K,A,Q)
AIPS 1: QUAL         -1                    Source qualifier -1=>all
AIPS 1: CALCODE    ' '                     Calibrator code
AIPS 1: VLAOBS     ' '                     VLA obs. pgm. name ('AZ99')
AIPS 1: VLAMODE    ' '                     VLA obs. mode ('  '=any)
AIPS 1: REFDATE    ' '                     Reference date. 'yyyymmdd'
AIPS 1: TIMERANG   *all 0                  Timerange selected
AIPS 1: BCHAN         1                    First spectral channel
AIPS 1: ECHAN         0                    Highest spectral channel
AIPS 1: OUTNAME    'TEST'                  Output UV file name (name)
AIPS 1: OUTSEQ        0                    Output UV file name (seq. #)
AIPS 1: OUTDISK       1                    Output UV file disk unit #.
AIPS 1: DOUVCOMP      1                    1 (T) => compressed data
AIPS 1: DOCONCAT     -1                    1 (T) => append data to old
AIPS 1:                                    files
AIPS 1: NCOUNT        1                    Number of files to read
AIPS 1: DOWEIGHT      1                    Use nominal sensitivity to
AIPS 1:                                    scale weights?
AIPS 1:                                    = 10, use Memo 108 weights
AIPS 1: DOACOR       -1                    Load autocorrelation data?
AIPS 1: CPARM         0           0        User options.
AIPS 1:               0           0        1 => Avg. time (seconds)
AIPS 1:               0           0        2 => bitmap    (see help)
AIPS 1:            6300        *rest 0          = 16 for planets & Sun
AIPS 1:                                    3 => Max. OK IF status
AIPS 1:                                         <=3 => 3
AIPS 1:                                    4 => Control dropping of
AIPS 1:                                         shadowed data
AIPS 1:                                         < 0 => no shadow check
AIPS 1:                                         0 => 25 m limit
AIPS 1:                                         > 0 => Shadow limit is
AIPS 1:                                               CPARM(4) in meters
AIPS 1:                                    5 = channel code (see HELP)
AIPS 1:                                    6 => Subarray number-see HELP
AIPS 1:                                    7 => FQ entry tolerance (kHz)
AIPS 1:                                         (see HELP)
AIPS 1:                                    8 => CL table time incr. min
AIPS 1:                                    9 => TY table time incr. min
AIPS 1:                                    10=> Calibrator avg. time
AIPS 1: DPARM      *all 0                  Selection by Frequency
AIPS 1:                                    1+2 => A Frequency (Hz)
AIPS 1:                                    3+4 => B Frequency (Hz)
AIPS 1:                                    5+6 => C Frequency (Hz)
AIPS 1:                                    7+8 => D Frequency (Hz)
AIPS 1:                                    9 => tolerance for A&C
AIPS 1:                                    10 => tolerance for B&D
AIPS 1: BPARM      *all 0                  Opacity and Gain curve
AIPS 1:                                    control (see help)
AIPS 1: IN2FILE    *all ' '                Antenna gains file


>From the scan listed on the VLA data archive website, this archived data contains
two IF band with frequency 23.69GHz and 23.72 GHz, respectively. And each of them
had been measured in 'RR' and 'LL'.
However, after loading the data into AIPS, I got two UV line data, with 23.69GHz band
in one file and 23.72GHz in the other. But the first file only contains 'RR' 
correlation, and the second file contains only 'LL' correlation.

Here are the header of each of them:

>imh
AIPS 1: Image=MULTI     (UV)         Filename=20001023    .LINE  .   1
AIPS 1: Telescope=VLA                Receiver=VLA
AIPS 1: Observer=AK517               User #=    2
AIPS 1: Observ. date=23-OCT-2000     Map date=18-OCT-2008
AIPS 1: # visibilities    113850     Sort order  TB
AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
AIPS 1:            SOURCE  FREQSEL  WEIGHT  SCALE
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
AIPS 1: COMPLEX      1   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        63   2.3696098E+10      32.00  9.7656250E+04    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: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 1950.00
AIPS 1: Maximum version number of extension files of type HI is   1
AIPS 1: Maximum version number of extension files of type AN 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 SU 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 CL is   1
AIPS 1: Maximum version number of extension files of type TY 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: Keyword = 'OBSCHANS'  value =           64
AIPS 1: Keyword = 'CORRMODE'  value = '2AD     '
AIPS 1: Keyword = 'SELCHANS'  value =           63
AIPS 1: Keyword = 'VLAIFS  '  value = 'A       '
AIPS 1: Keyword = 'CORRCOEF'  value =           -1


AIPS 1: Image=MULTI     (UV)         Filename=TEST        .LINE  .   2
AIPS 1: Telescope=VLA                Receiver=VLA
AIPS 1: Observer=AK517               User #=    2
AIPS 1: Observ. date=23-OCT-2000     Map date=20-OCT-2008
AIPS 1: # visibilities    115324     Sort order  TB
AIPS 1: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  BASELINE  TIME1
AIPS 1:            SOURCE  FREQSEL  WEIGHT  SCALE
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
AIPS 1: COMPLEX      1   1.0000000E+00       1.00  1.0000000E+00    0.00
AIPS 1: STOKES       1  -2.0000000E+00       1.00 -1.0000000E+00    0.00
AIPS 1: FREQ        63   2.3724238E+10      32.00  9.7656250E+04    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: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 1950.00
AIPS 1: Maximum version number of extension files of type HI is   1
AIPS 1: Maximum version number of extension files of type AN 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 SU 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 CL is   1
AIPS 1: Maximum version number of extension files of type TY 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: Keyword = 'OBSCHANS'  value =           64
AIPS 1: Keyword = 'CORRMODE'  value = '2AD     '
AIPS 1: Keyword = 'SELCHANS'  value =           63
AIPS 1: Keyword = 'VLAIFS  '  value = 'D       '
AIPS 1: Keyword = 'CORRCOEF'  value =           -1


If I use LISTR to show the scan of the first UV file with STOKES set to be 'LL', then
it shows no flux is detected from 'LL'


 hyliu     LISTR(31DEC08)      2     21-OCT-2008  08:19:15    Page    1
File = 20001023    .LINE  .   1 Vol = 1  Userid =    2
Freq = 23.696097626 GHz   Ncor =  1   No. vis =    113850
Scan summary listing

Scan      Source      Qual  Calcode Sub         Timerange          FrqID   START VIS 
END VIS
   1 1328+307        : 0000  A        1  0/20:31:15 -   0/20:31:15     1       1          0
   2 1328+307        : 0000  A        1  0/20:31:25 -   0/20:40:35     1       1      15513
   3 1226+023        : 0000  A        1  0/20:41:55 -   0/20:50:35     1   15514      29218
   4 1730-130        : 0000  A        1  0/20:53:15 -   0/20:56:35     1   29219      34580
   5 G106            : 0000           1  0/20:57:15 -   0/21:12:25     1   34581      57583
   6 1730-130        : 0000  A        1  0/21:13:05 -   0/21:16:25     1   57584      62189
   7 G106            : 0000           1  0/21:17:05 -   0/21:32:25     1   62190      86178
   8 1730-130        : 0000  A        1  0/21:33:05 -   0/21:36:25     1   86179      92135
   9 G106            : 0000           1  0/21:37:05 -   0/21:48:55     1   92136     113850

Source summary
Velocity type = 'LSR     '    Definition = 'RADIO   '

  ID Source           Qual  Calcode RA(1950.0)     Dec(1950.0)   IFlux   QFlux   UFlux 
 VFlux  No. vis
   1 1328+307        : 0000   A     13:28:49.6579  30:45:58.641   0.000   0.000   0.000
  0.000   15513
   2 1226+023        : 0000   A     12:26:33.2458  02:19:43.306   0.000   0.000   0.000
  0.000   13705
   3 1730-130        : 0000   A     17:30:13.5352 -13:02:45.840   0.000   0.000   0.000
  0.000   15925
   4 G106            : 0000         18:07:30.6800 -19:56:28.400   0.000   0.000   0.000
  0.000   68707

  ID Source            Freq(GHz) Velocity(Km/s) Rest freq (GHz)
   1 1328+307            23.6961         0.0000         23.6945
   2 1226+023            23.6957         0.0000         23.6945
   3 1730-130            23.6938         0.0000         23.6945
   4 G106                23.6935         0.0000         23.6945

Frequency Table summary
FQID IF#      Freq(GHz)      BW(kHz)   Ch.Sep(kHz)  Sideband
   1   1      23.69609763    6250.0005     97.6563      1
AIPS 1: Resumes



 It seems that, while loading data, the correlator mode is not interpretated 
correctly. I also got similar problem to load the archived data AK0138. From 
the archive data website, I should have both 'RR' and 'LL', and the correlator
mode is '2A'. However, I can only load the 'RR' data into AIPS, and has the
VLA IF 'A'. Is there any parameter to tune to load the data correctly? Thanks 
for the helping.


best wish,
Hauyu

--
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---------- Original Message -----------
From: Eric Greisen <egreisen at nrao.edu>
To: Hau Yu Liu <hyliu at asiaa.sinica.edu.tw>
Cc: daip at nrao.edu
Sent: Mon, 20 Oct 2008 13:06:27 -0600
Subject: Your query of the analysts

> Please use daip at nrao.edu for queries about aips.
> 
> Can you send me the display you get for each of the uv files when
> you do an IMHEADER.
> 
> The PRTUV is showing you the first 4 channels of a data set that I am 
> assuming is only 1 polarization.  The display from LISTR with OPTYPE 
> 'SCAN' would also be useful.
> 
> Eric Greisen
------- End of Original Message -------




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