x_list

       x_list  -  Extract  Cross-Over  Information  from the Data
       Base.

SYNOPSIS

       x_list  [  leg1  ]   [   leg2   ]   [   -dataflags   ]   [
       -Rwest/east/south/north ] [ -Xxbase ] [ -H ] [ -I ] [ -V ]
       [ -Ccorrfile ] [ -Zignorefile ]

DESCRIPTION

       x_list will allow the user to extract information from the
       xx_base.b  and  xx_legs.b  files.   Several options can be
       passed on the command  line  in  order  to  specify  which
       parameters to extract. They are:

       leg1 leg2
              If  two  legs  are  specified, the cross-overs they
              have in common are returned. If one leg  is  speci­
              fied,  all  the external cross-overs involving this
              leg are returned, OR only its internal  cross-overs
              if  -I  is  selected. If no legs are given, all the
              external (or  internal  with  -I)  cross-overs  are
              returned.  This  program  is useful if one wants to
              look at, say, gravity COEs versus  time  from  port
              for a particular leg, etc.

       dataflags
              This  is a string of any combination of the follow­
              ing:
                      l means list both legnames.
                      t means list time.
                      x means list longitude.
                      y means list latitude.
                      g means list gravity COEs.
                      m means list magnetics COEs.
                      b means list bathymetry COEs.
                      G means list average gravity at cross-over.
                      M  means  list  average magnetic anomaly at
              cross-over.
                      B means list average bathymetry  at  cross-
              over.
                      h means list heading of ship at cross-over.
              The components are written out in  the  order  they
              appear  in dataflags. The default output is -txygm­
              bGMBhl. When internal COEs are  desired,  the  time
              reported  is  the elapsed time since the ship first
              occupied the cross-over point.  For  external  COEs
              the  time  means time from the start of the year in
              seconds.

       -R     Only return cross-overs inside the specified region
              west, east, south, and north. [Default is world].


       -I     Report on internal COEs [Default is external COEs].

       -C     Apply  cross-over  correction  to  the  data  (i.e.
              reports the cross-over value after the best-fitting
              corrections have been applied to both legs). If  no
              corrfile  is  given, the default correction file is
              assumed.

       -Z     Ignore those legs that appear in the ignorefile.

       -V     Operate in verbose mode.

SEE ALSO

       gmt(l), x_system(l)

REFERENCES

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