NAME

       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     Selects  verbose  mode,  which  will  send progress reports to stderr [Default runs
              "silently"].  Reports the pair currently being processed.

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

BEWARE

       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 recommended 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(1), x_system(1)

REFERENCES

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