SLOT_FIX (Mar95)                suntrans                SLOT_FIX (Mar95)



NAME
    SLOT_FIX -- put time sample numbers in the image headers for a  time
    ordered  list   of  images.   Keep, add or replace UT time stamps as
    needed.
    
    
USAGE
    slot_fix inputl epoch nstart (del_image seconds head_replace)
    
    
PARAMETERS
    
    inputl
        input list of files or template for input files
    
    epoch
        date and time for slot nstart UT, format yyyy/mm/dd.hh:mm:ss
    
    nstart
        slot number for the epoch above, commonly 0
    
    (del_image = 60)
        spacing between time samples in seconds
    
    (seconds = no)
        should the value of the seconds  be  considered  when  computing
        the time sample numbers?
    
    (head_replace = yes)
        Should existing date and time header words be replaces?
    
    
IMAGE HEADERS
    
    DATE-OBS
        UT date of image, format yyyy/mm/dd.
    
    TIME-OBS
        UT time of image, format hh:mm:ss.
    
    UT_DATE
        Old  GONG  header for UT date of image, format yy/mm/dd.  If the
        DATE-OBS header is not found, this header is checked.
    
    UT_TIME
        Old GONG header for UT time of image, format hh:mm:ss.   If  the
        TIME-OBS header is not found, this header is checked.
    
    
DESCRIPTION
    Task  SLOT_FIX  writes  into  the  image header a time sample number
    and, if requested computes and writes into the  image  header  a  UT
    date  and  time  for  use in ephemeris calculations.  For older GONG
    data, the headers UT_DATE and UT_TIME are rewritten as DATE-OBS  and
    TIME-OBS.   If  neither  header  is  present, sequential time sample
    numbers are written into the headers beginning  with  sample  number
    nstart+1  with  UT dates and times consistent with the epoch and the
    time sample spacing.
    
    
EXAMPLES
    
    1.  The time sample numbers are written  into  the  headers  of  the
    images  in list lis.oct30.  The epoch to be used is UT time 15:40:20
    on October 30, 1992.  The existing UT date and time  stamps  already
    in the image headers are retained.
    
            su> slot_fix @lis.oct30 "1992/10/30.15:14:20" 0 head_replace=no
    
    2.   The  time  sample  numbers are written into the headers of each
    image in list input.lis.  As the data is not GONG data,  neither  of
    the  recognized  header  words  for  time  stamps are present in the
    image headers.  The UT date and time for  the  first  image  in  the
    list  is  July  3,  1988  at 22:06:00 and should be sample 101.  The
    images were taken 60 seconds apart.
    
            su> slot_fix @input.lis "1988/07/03.22:05:00" 100 head_replace=yes 
    
    2.  The images are in the list  lis.ju6v.   The  UT  date  and  time
    stamps  in  the image headers are to be replaced, as they are in the
    old GONG format.  (The original UT date and time stamps are  written
    into  another  image  header  word for reference.)   The images were
    recorded 75 seconds apart, and as a consequence,  the  seconds  must
    be  considered when computing the slot number.  The UT date and time
    for the  first  image  in  the  list  was  taken  July  6,  1989  at
    10:27:06.
            su> slot_fix @lis.ju6v "1989/07/06.10:27:06" del_image=75 seconds=yes
    
    
    
TIME REQUIREMENTS
    minimal--less than 10 seconds elapsed time for 60 images.
    
    
BUGS
    None known.
    
    
SEE ALSO