Software documentation: Caget

10-OCT-1996

Preface

CAGET is a package designed to provide a history of readily accessible visibilities from the Australia Telescope Compact Array. These data are loaded into a file with a cyclic structure once every integration cycle. Each record holds the raw, spectrally averaged, astronomical data. When the file is filled, the oldest data are overwritten, thus the file is never closed.

Call sequence: 

      program caget
      implicit none
      include 'array_inc:array_gs.inc'
      include 'array_inc:a_data.inc'
      include 'caobs$inc:caobs_status.inc'
      include 'constants'
      include 'caget$inc:caget_main.inc'
      record  /getvis/buffer(0:3)
Creation date: 12-Jan-1994

Author: Derek McKay (based on an original by David McConnell)

File: CAGET.FOR

Routine name: epochnm

Function:

Convert the epoch into a code. 

 
                 0 = J2000
                 1 = B1950
                 2 = AZEL

Call sequence: 

      byte function epochnum(epoch)
      implicit none
      character*(*) epoch
Creation date: 12-Jan-1994

Author: David McConnell

File: CAGET.FOR

Routine name: initperm

Function:

Sorts out the mapping between visibilities, as delivered by CACOR, and the interferometer pairs.

Call sequence: 

      subroutine initperm(nfrq,perm)
      implicit none
      integer nfrq                ! number of frequencies in use
      integer perm(1:21,1:4,1:2)  ! Mapping from vis number to baseline
      include 'caobs$inc:caobs_status.inc'
Creation date: 12-Jan-1994

Author: David McConnell

File: CAGET.FOR

Routine name: station_pos

Function:

Returns the station position as a distance from station CS01.

Call sequence: 

      real function station_pos(station)
      implicit none
      integer station
Creation date: 12-Jan-1994

Author: David McConnell

File: CAGET.FOR

Routine name: getmuvw

Function:

To compute the transformation matrix MUVW which is used to compute vector Vuvw: 

                Vuvw = Muvw x B
where B is the unit baseline vector.

Call sequence: 

      subroutine getmuvw(ra,dec,muvw)
      implicit none
      double precision ra,dec
      double precision muvw(3,3)
Creation date: 23-JAN-1992

Function:

_ To calculate the precession matrix P for dates AFTER 1984.0 (JD = 2445700.5) Given the position of an object referred to the equator and equinox of the epoch Js (TDB) its position referred to the equator and equinox of epoch Je (TDB) can be calculated as follows : express position as directcosine 3-vector, V1 then the corresponding vector V2 for epoch Js is V2 = P.V1

Call sequence:

_ precsn(Js, Je, P) Author: _ D. McConnell

File: VECTORS.FOR

Routine name: getuvw

Function:

To compute the unit vector (u,v,w) : Vuvw. The unit baseline vector UB points westwards along the array. UB is computed relative to the equator and equinox of J2000. Then 

                Vuvw = Muvw x UB

Call sequence: 

 
      subroutine getuvw(utc, long, muvw, vuvw)
 
      implicit none
 
      double precision   utc,           !  UTC as TJD
     -                   long,          ! observatory longitude
     -                   muvw(3,3),     ! UVW direction cosine matrix
     -                   vuvw(3)        ! UVW unit vector
Creation date: 23-JAN-1992

Include file: getvis.inc

Function:

Defines the structure of CAGET records. The visibilities and delays are mapped as follows: 1:21 - baselines 1-6 = 11,22,...,66, 7-21 = 12,13,14,...,56 1:4 - polarisations XX,XY,YX,YY 1:2 - frequencies

Creation date: 19-Aug-1996

Author: David McConnell & Derek McKay

File: GETVIS.INC

Include file: snap

Include file: caget.inc

Function:

This include file contains the definitions of the CAGET records

Creation date: 19-Aug-1996

Author: David McConnell & Derek McKay

File: CAGET.INC

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