NAME

       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
              specified, 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 following:
                   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
              -txygmbGMBhl.  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].

       -X     Indicate alternate xx_base.b file.

       -H     Issue one header record on output.

       -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     Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].

SEE ALSO

       GMT(1), x_system(1)

REFERENCES

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

GMT 4.5.11                                         5 Nov 2013                                       X_LIST(1gmt)