[daip] FITLD bug

Amy Mioduszewski amiodusz at aoc.nrao.edu
Thu Sep 27 11:37:47 EDT 2001


I am seeing this really bizarre FITLD problem.  I am trying
to load an experiment which has 4 frequencies, but FITLD
keeps finding 7 FREQIDs.  Two are imaginary (i.e. I didn't
observe one and one of the is even negative) and one is a
repeat of another frequency.  I checked the correlator jobs
to make sure there is nothing strange about them and they are
fine.

I have tried TST, NEW and OLD and they all give the same
thing.  I tried loading the files in separately and the problem
seems to be with the first file.  I even had the first file
redistributed, to see and it is the same.  I acknowledge there
might be something strange in the correlation but AIPS is still
not dealing with it correctly.  Any ideas?

Here is the file header and PRTTP of the FQ table:

AIPS 5: Image=MULTI     (UV)         Filename=BM126H      .UVDATA.   1
AIPS 5: Telescope=VLBA               Receiver=VLBA
AIPS 5: Observer=BM126               User #= 1709
AIPS 5: Observ. date=18-SEP-2001     Map date=26-SEP-2001
AIPS 5: # visibilities    520032     Sort order  TB
AIPS 5: Rand axes: UU-L-SIN  VV-L-SIN  WW-L-SIN  TIME1  BASELINE
AIPS 5:            SOURCE  FREQSEL  INTTIM  GATEID  CORR-ID
AIPS 5: ----------------------------------------------------------------
AIPS 5: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
AIPS 5: COMPLEX      3   1.0000000E+00       1.00  1.0000000E+00    0.00
AIPS 5: STOKES       4  -1.0000000E+00       1.00 -1.0000000E+00    0.00
AIPS 5: FREQ        16   4.9874900E+09       0.56  5.0000000E+05    0.00
AIPS 5: IF           2   1.0000000E+00       1.00  1.0000000E+00    0.00
AIPS 5: RA           1    00 00 00.000       1.00       0.000000    0.00
AIPS 5: DEC          1    00 00 00.000       1.00       0.000000    0.00
AIPS 5: ----------------------------------------------------------------
AIPS 5: Coordinate equinox 2000.00
AIPS 5: Maximum version number of extension files of type HI is   1
AIPS 5: Maximum version number of extension files of type AT is   1
AIPS 5: Maximum version number of extension files of type IM is   1
AIPS 5: Maximum version number of extension files of type CT is   1
AIPS 5: Maximum version number of extension files of type MC is   1
AIPS 5: Maximum version number of extension files of type OB is   1
AIPS 5: Maximum version number of extension files of type GC is   1
AIPS 5: Maximum version number of extension files of type TY is   1
AIPS 5: Maximum version number of extension files of type WX is   1
AIPS 5: Maximum version number of extension files of type PC is   1
AIPS 5: Maximum version number of extension files of type NX is   1
AIPS 5: Maximum version number of extension files of type CL is   1
AIPS 5: Maximum version number of extension files of type FQ is   1
AIPS 5: Maximum version number of extension files of type AN is   1
AIPS 5: Maximum version number of extension files of type SU is   1
AIPS 5: Maximum version number of extension files of type CQ is   1
AIPS 5: Maximum version number of extension files of type FG is   1
AIPS 5: Keyword = 'OLDRFQ  '  value =  4.98749000E+09

BM126H      .UVDATA.   1  Disk= 2    FQ Table version   1
Title: AIPS UV DATA FILE FREQUENCY TABLE
Created by      FITLD on 26-SEP-2001 15:33:45
Last written by FITLD on 26-SEP-2001 15:37:59
Ncol   5  Nrow       7    Sort cols:
    Table has     1 keyword-value pairs:
   NO_IF    =            2
   Table format incompatable with FITS ASCII tables

COL. NO.        1             2               3             4             5
     ROW     FRQSEL     IF FREQ           CH WIDTH      TOTAL BAN     SIDEBAND
  NUMBER                HZ                HZ            HZ
       1        4        0.000000E+00     5.000E+05     8.000E+06         1
       1                 8.000000E+06     5.000E+05     8.000E+06         1
       2        2        6.868000E+09     5.000E+05     8.000E+06         1
       2                 6.876000E+09     5.000E+05     8.000E+06         1
       3        3       -1.369800E+10     5.000E+05     8.000E+06         1
       3                -1.369000E+10     5.000E+05     8.000E+06         1
       4        1        0.000000E+00     5.000E+05     8.000E+06         1
       4                 8.000000E+06     5.000E+05     8.000E+06         1
       5        5        1.723800E+10     5.000E+05     8.000E+06         1
       5                 1.724600E+10     5.000E+05     8.000E+06         1
       6        6       -3.328000E+09     5.000E+05     8.000E+06         1
       6                -3.320000E+09     5.000E+05     8.000E+06         1
       7        7        1.037000E+10     5.000E+05     8.000E+06         1
       7                 1.037800E+10     5.000E+05     8.000E+06         1

I observed FREQIDs 4, 1 , 5, 6, 7 (i.e. 22, 15, 5 & 1.6 GHz).

Here are my inputs:
AIPS 5: FITLD:  Task to store an image or UV data from a FITS tape
AIPS 5: Adverbs     Values                 Comments
AIPS 5: ----------------------------------------------------------------
AIPS 5: INTAPE        2                    Input tape drive # (0 => 1)
AIPS 5: NFILES        0                    # of files to advance on tape
AIPS 5: INFILE     *all ' '                Disk file name (FITS only)
AIPS 5: OUTNAME    'BM126H      '          File name (name)
AIPS 5: OUTCLASS   '      '                File name (class)
AIPS 5: OUTSEQ        0                    File name (seq. #)
AIPS 5:                                       0 => highest unique number
AIPS 5:                                         => matching (on VLBA)
AIPS 5:                                      -1 => FITS tape value
AIPS 5: OUTDISK       2                    Disk drive # (0 => any)
AIPS 5: OPTYPE     '    '                  Type of data to load,
AIPS 5:                                    '  ' => all types
AIPS 5:                                    'UV' => UV data
AIPS 5:                                    'IM' => images
AIPS 5: NCOUNT       11                    Number of files to load.
AIPS 5: DOTABLE       1                    True (1.0) means load tables
AIPS 5:                                    for images.
AIPS 5: DOUVCOMP     -1                    >0 => compressed data (FITS)
AIPS 5: DOCONCAT      1                    >0 -> if VLBA or uv table,
AIPS 5:                                    append data to existing
AIPS 5:                                    files, or if no appropriate
AIPS 5:                                    files exist create a new file
AIPS 5:                                    and append all data to that
AIPS 5:                                    file.
AIPS 5:                                    *****************************
AIPS 5:                                    Following adverbs are useful
AIPS 5:                                    only when reading VLBA
AIPS 5:                                    distribution tapes.
AIPS 5:                                    *****************************
AIPS 5: CLINT         0                    CL entry interval (min)
AIPS 5:                                    0 => 1 minute.
AIPS 5: SOURCES    *all ' '                Source list to accept.
AIPS 5: QUAL         -1                    Source qualifier -1=>all
AIPS 5: TIMERANG   *all 0                  Timerange selected
AIPS 5: BCHAN         1                    Lowest spectral channel
AIPS 5:                                    number to select in each IF.
AIPS 5:                                    0=>1
AIPS 5: ECHAN         0                    Highest spectral channel
AIPS 5:                                    number to select in each IF.
AIPS 5:                                    0=>highest
AIPS 5: BIF           0                    Lowest IF number 0=>1
AIPS 5: EIF           0                    Highest IF number 0=>all
AIPS 5: DIGICOR       1                    Controls the application of
AIPS 5:                                    the VLBA correlator's digital
AIPS 5:                                    correction.
AIPS 5:                                    0 or 1 => perform corrections
AIPS 5:                                    2 => perform cross-power
AIPS 5:                                      corrections, do total-power
AIPS 5:                                      only if zero padding used.
AIPS 5:                                    -1 => do NOT perform
AIPS 5:                                      corrections.
AIPS 5:                                    SEE HELP for more details
AIPS 5: SELBAND      -1                    Bandwidth to select (kHz)
AIPS 5: SELFREQ      -1                    Frequency to select (MHz).
AIPS 5:                                    See HELP.
AIPS 5: FQTOL        -1                    Frequency tolerance assigned
AIPS 5:                                    to SELFREQ, FITLD will select
AIPS 5:                                    data with freq. of SELFREQ
AIPS 5:                                    +/- FQTOL.
AIPS 5:                                    The unit of FQTOL is kHz.
AIPS 5:                                    <=0 => 10 kHz
AIPS 5: WTTHRESH      0.8                  Flagging threshold based on
AIPS 5:                                    weights. See HELP.
AIPS 5:                                    0 => no flagging
AIPS 5:                                    1 => will flag ALL data
AIPS 5: OPCODE     '    '                  Specify if wish to keep VT
AIPS 5:                                    (VLBA Tape Statistics) table.
AIPS 5:                                    '  ' => do not copy VT table
AIPS 5:                                    'VT' => keep VT table
AIPS 5: NPIECE        0                    Maximum uv table piece to
AIPS 5:                                    load (ignored for tape unless
AIPS 5:                                    NCOUNT = 1)

If you want to see the FITLD messages I have saved them to a file
/export/home/beset/amy/XRB/CygX3/bm126h/fitld.

Cheers,

Amy




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