MODIFY FOCUS

 

        CLIC\MODIFY FOCUS antenna1 value1  antenna2 value2 ...

    Correct the phases for the offsets  in  focus,  introduced  to  optimize
    efficiency.   A1  is  the antenna number, value1 the focus offset in mm,
    and so on.  The phases are normally corrected in  real  time  since  29-
    nov-1996.   Between  29-may-1996  and 29-nov-1996, the focus corrections
    were logged in the data files. Before 29-may-1996 they are only  in  the
    log-obs   files.   However  between  29-nov-1996  and  02-apr-1998,  the
    correction had wrong sign for the few projects using HIGH LOCK.

    So use MODIFY FOCUS with NO arguments for data more recent that  29-nov-
    1996:  this  should  correct the HIGH LOCK problem.  Between 29-may-1996
    and 29-nov-1996, MODIFY FOCUS with  no  arguments  will  use  the  focus
    offsets in the header and apply the corresponding phase offsets.

    For older data you may now search for the focus changes in the log files
    to  apply  the phase corrections before calibration; or use jumps in the
    phase calibration just as you had done before.


    This command applies to the current index; an output file must  be  open
    (may  be equal to the input file).