x_update

       x_update - Archiving of Cross-Over Information

SYNOPSIS

       x_update cross-overfile [ -Xxbase ] [ -Llegbase ] [ -V ] [
       -Wmax ]

DESCRIPTION

       x_update reads the  ASCII  file  produced  by  x_over  and
       writes the information to the database files xx_base.b and
       xx_legs.b (unless other filenames  are  specified  on  the
       command  line) using a compact, binary format. The options
       recognized are:

       -X     Indicate alternate xx_base.b file.

       -L     Indicate alternate xx_legs.b file.

       -V     Verbose. Reports  the  pair  currently  being  pro­
              cessed.

       -W     Prints a warning if the number of COEs generated by
              any pair of legs exceed max.

For security reasons the xx_legs.b are first renamed to

       xx_legs.b_old, to prevent loss of
       information  if  a  black-out or system crash should occur
       during writing of the new xx_legs.b  file.  It  is  recom­
       mended  that  the  old file is left on the disk in case of
       other disasters. Note that x_update does not  check  if  a
       pair  of  legs  already exist in the xx_base.b file. It is
       the user's' responsibility to ensure that  duplication  of
       information  does  not occur. Should some pairs already in
       the database need to be  re-examined,  then  run  x_remove
       which  will  wipe  out all traces of the specified cruises
       from the x_system data base files. Now  we  can  pass  the
       pairs  that  need  to  be  redone  through x_over/x_update
       again.

SEE ALSO

       gmt(l), x_system(l)

REFERENCES

       Wessel, P. XOVER: A Cross-over Error  Detector  for  Track
       Data, Computers & Geosciences, 15, 333-346.