How to update tempo's UT1 corrections

  • The final ut1.dat file is held in $TEMPO/clock. Working files and utilities are held in $TEMPO/clock/ut1_updates.
  • You should be able to download the latest ut1.dat from (Arecibo). Save it in the ut1_updates directory and put a copy in the clock directory.
  • Feb 08: This method is currently broken, from bulletin 139 onwards (they've changed the format and the script need updating!)
    Browse to  and download the highest numbered (latest) bulletinb.XXX to the ut1_updates directory (and any intermediate bulletins that you may need).
  • Run do.iers.ut1 (in $TEMPO/clock/ut1_update) on each bulletin: 

  • (Make sure any new leap seconds get added to @leapmjd array in do.iers.ut1). 
    example: do.iers.ut1 bull/bulletinb.128 > ut1.128
  • Append ut1.xx to $TEMPO/clock/ut1_updates/ut1.dat. First five numbers should be updates to projected values from previous ut1.xx; last five numbers should be new (projected) values.
  • If the last line of ut1.dat is incomplete -- it typically has four entries instead of the usual six -- then the number of entries ('4') should be in column 60 of the last line. Column 60 of other lines should be blank.
  • Run check.ut1 to do a 'sanity check' on the new ut1.dat file
  • Copy the updated file to $TEMPO/clock/ut1.dat.

Derived from $TEMPO/clock/ut1_updates/0readme.txt by Ingrid Stairs. 23rd Oct 2000 
-  site address updated Oct 2 2002 Caj.


Oct 2, 2002