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Antenna files         ANdssvv
 
 
A. Overview
 
Function: This extension table for a uv data set contains information
about the antennas and the array geometry including conversion from
atomic time to sidereal time.
 
Details: AN files use the TABINI-TABIO files.
 
Names: The file name is ANdsssvv where d is disk number, sss=catalog
number and vv = version number.
 
B.  File structure.

     Logical records consist of the information for a single antenna.
In the case of an orbiting antenna the elements of the orbit are given.
For each antenna two polarization feeds are assumed (A and B)
For orbiting antennas the orbital elements are given by ORBPARM
 
    The file header record contains the following KEYWORDs:
 

     Keyword type    Description
   --------- ---- ---------------------------------------------------
     ARRAYX   D    Array center X coord. (meters, earth center)
     ARRAYY   D    Array center Y coord.
     ARRAYZ   D    Array center Z coord.
     GSTIA0   D    GST at IAT=0 (degrees) on ref. date
     DEGPDY   D    Earth rotation rate (deg/IAT day)
     FREQ     D    Obs. Reference Frequency for subarray(Hz)
     RDATE    A    Reference date as 'DD/MM/YY'
     POLARX   E    Polar position X (meters) on ref. date
     POLARY   E    Polar position Y (meters)     "
     UT1UTC   E    UT1-UTC  (time sec.)          "
     IATUTC   E    IAT-UTC  (time sec.)          "
     ARRNAM   A    Array name
     NUMORB   I    Number of orbital parameters
     NOPCAL   I    Number of polarization calibration constants.
     POLTYPE  A    Polarization type 'APPROX' or 'ORI-ELP'.
 
   Table entries:

       Title          Units   Code        Description
  ----------------- --------  ----  ------------------------------------
     ANNAME                    8A   Station name
     STABXYZ          meters   3D   X,Y,Z offset from array center
     ORBPARM                   *D   Orbital parameters (see note 1)
     NOSTA                     1I   Station number
     MNTSTA                    1I   Mount type, 0=altaz, 1=equatorial,
                                    2=orbiting
     STAXOF           meters   1E   Axis offset
     POLTYA                    1A   Feed A feed poln. type 'R','L','X','Y'
     POLAA            degrees  1E   Feed A feed position angle.
     POLCALA                   *E   Feed A poln. cal parameter. (note 2)
     POLTYB                    1A   Feed B feed poln. type 'R','L','X','Y'
     POLAB            degrees  1E   Feed B feed position angle.
     POLCALB                   *E   Feed B poln. cal parameters.
 
 
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.  ORBPARM is an array whose dimension is given by the header
keyword NUMORB

     Note 2.  POLCALA and POLCALB are arrays whose dimension is given by
the header keyword NOPCAL.

 
D.  Routines to write AN files:
     TABINI and TABIO,  AN files are currently written by UVLOD and
TOAIP.
 
 
E.  Routines to access AN files: TABINI and TABIO.
