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Baseline table         BLdssvv
 

 
A. Overview
 
   This table contains complex gains for each baseline necessary to
correct for non antenna based errors.  These errors are assumed to
consist of a multiplicative and an additive portion.
 
Names: The file name is BLrsssvv where r is the AIPS release number,
sss=catalog number and vv = version number.
 
B.  File structure.

    Logical records consist of the information for a single baseline at
a given time and for a given FRQSEL number for all IFs and polarizations.
 
    The file header record contains the following KEYWORDs:
     Keyword  Code   Description
     -------- ----  ---------------------------------------------------
     NO_ANT   I     The number of antennas for which there is
                    information
     NO_POL   I     The number of polarizations
     NO_IF    I     The number of IFs.
 
   Table entries:

       Title          Units   code      Description
  ----------------- --------- ---- -------------------------------------------
    TIME              Days    1E   Time of center of interval since 0h on
                                   reference day.
 
    SOURCE ID                 1I   Identification number of the source used.
    SUBARRAY                  1I   Subarray number
    ANTENNA1                  1I   First antenna number.
    ANTENNA2                  1I   Second antenna number.
    FREQ ID                   1I   Frequency ID number
    REAL M1                   *E   Real part of multiplicative factor for
                                   first polarization. (see note 1)
    IMAG M1                   *E   Imag. part of multiplicative factor for
                                   first polarization.
    REAL A1                   *E   Real part of additive correction for
                                   first polarization.
    IMAG A1                   *E   Imag. part of additive correction for
                                   first polarization.

The following are present only if NO_POL = 2

       Title          Units  code      Description
  ----------------- -------- ----  ---------------------------------------
    REAL M2                   *E   Real part of multiplicative factor for
                                   second polarization. (see note 1)
    IMAG M2                   *E   Imag. part of multiplicative factor for
                                   second polarization.
    REAL A2                   *E   Real part of additive correction for
                                   second polarization.
    IMAG A2                   *E   Imag. part of additive correction for
                                   second polarization.


C. User notes.

  The "code" column is element_count + basic type code.
basic type codes: D=Double precision, E=single precision,
   A=character, J=long integer, L=logical, I=short integer, X=bit.

     Note 1. REALM1, IMAGM1, REALA1, IMAGA1, REALM2, IMAGM2, REALA2 and
IMAGA2 are arrays whose dismesions are given by the header keyword NO_IF.


     This table will in practice be used only by standard interface
routines.
 
D.  Routines to write BL files:
     The AIPS routines BLINI and TABBL will create/read/write BL tables.
Chapter 13 of "Going AIPS" given a detailed description of routines to
access tables files.
 
E.  Routines to access BL files:
     Chapter 13 of "Going AIPS" given a detailed description of routines to
access tables files.
