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 Get BULL_B or BULL_A Pole and UT1 tables.  
  
 There are two modes of use: 
  
 (1) Always get new tables regardless of current tables ranges (if no date entered)
 (2) Get new tables if the requested date is outside the range of the current tables
  
 Usage: sh_update_eop -series <eops> -jd <jd> -yr <yr> -doy <doy> -perror <val> -pmax <num> -min <min> -noftp <Y/N> -ftp_prog <ftp/ncftp>
  
        <eops>  is pole and ut1 series to be downloaded and checked. [Required] 
                For near realtime processing use usnd which contains on recent
                values (last 3 months) but is updated daily
        <jd>    is julian day of data to be processed. [Optional] 
                                    OR 
        <yr & doy>  are the year and day of year of data to be processed. [Optional]
  
        <num> is the maximum number of predicted values allowed [Default = 8].  The -perror
              value is checked before applying this limit.  If <num> is increased, then perror
              may also need to be increased
        <val> is the maximum predicted value error allowed (arc secs) when 
              NOTE: pmax has precidence over perror.
        <min> update the eop file if there are fewer than min entries after
              the date given [default 7 (also min allowed for interp.) and consistent with --pmax default].
        -noftp = Y Don't attempt to ftp updates, just check existing files. [Default = N]
        -ftp_prog is the name of the ftp program e.g. ftp or ncftp [default is ftp]
  
              writing predicted values into the bull_a tables. [Default 0.01] 
  
 Examples: sh_update_eop -series usno -yr 1998 -doy 235 -ftp_prog ncftp
           sh_update_eop -series usno -jd 2451048 
           sh_update_eop -series usno -perror 0.01 
           sh_update_eop -series usno 
  
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