## NAME

          gmtlist - A data-extractor for <legid>.gmt files

## SYNOPSIS

          gmtlist leg-ids [ -Ccorrectionfile ] [ -Dastartdate ] [ -Dbstopdate ] [
          -Fflags ] [ -G ] [ -H ] [ -Rwest/east/south/north ] [ -Sastartdist ] [
          -Sbstopdist ] [ -V ] [ -Wweight ] [ -b ]

## DESCRIPTION

          gmtlist reads <legid>.gmt files and produces an ASCII [or binary]
          table.  The <legid>.gmt files contain time(s), latitude(y),
          longitude(x), gravity(g/G), magnetics(m/M), and bathymetry(t/T), and
          the user may extract any combination of these 6 parameters +
          distance(d), heading (h), velocity (v), and weight (w, see -W).  A
          sub-section can be specified by passing time- or distance-intervals
          along track or by selecting a region.

          leg-ids
               Can be one or more cruisenames. To give a list of names, use `cat
               list_of_legs`.

## OPTIONS

          No space between the option flag and the associated arguments

          -C   Apply crossover Corrections to the data. If no correction file is
               given, gmtlist reads the default correction file. (See XSYSTEM
               for how to set up your own correction file)

          -Da  Do not list data collected before startdate (mm/dd/yyyy/hh:mm)
               [Default is first day].

          -Db  Do not list data collected after stopdate (mm/dd/yyyy/hh:mm).
               [Default is last day].

          -F   Can be any combination of syxgmtdhv to indicate the desired
               output data. The data will appear in the order indicated by
               flags. If GMT is substituted for gmt, only records that have that
               combination of data are written out. If s is followed by c
               (calender), then yyyy/mm/dd/hh/mm/ss is written out, if s is
               followed by j (julian), then yyyy/jd/hh/mm/ss is written out.
               Default is seconds from start of year.

          -G   Force Geographical longitudes (-180/+180) rather than geodetic
               (0-360) [Default].

          -H   Issue a header record with names for each data field.

          -Sa  Do not list data that are less than startdist km along track from
               port of departure. [Default is 0].

          -Sb  Do not list data that are more than stopdist km along track from
               port of departure. [Default is length of track].

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

          -W   Set the weight for these data.  Weight output option must be set
               in -F.  This is useful if the data are to be processed with the
               weighted averaging techniques offered by blockmean, blockmedian,
               and blockmode.

          -b   Selects binary output mode (in double precision) [Default is
               ASCII].  -H is ignored if -b is selected.  Julian and calender
               dates are not supported for binary time output (i.e., you get
               seconds from start of year).

## EXAMPLES

          To get a (distance, heading, crossover-corrected gravity, bathymetry)
          listing from c2104.gmt, starting at June 3 1971 20:45 and ending at
          distance = 5000 km, use the following command:

          gmtlist c2104 -Da6/3/1971/20:45 -Sb5000 -Fdhgt -C > myfile

          To make input for blockmean and surface using all the cruises listed
          in the file gmt.list, but only the data that are inside the specified
          area, and make output binary, try:

          gmtlist `cat gmt.list` -Fxyg -R-40/-30/25/35 -b > allgrav.xyg

## SEE ALSO

          gmt, xsystem

## REFERENCES

          Wessel, P., and W. H. F. Smith, 1999, The Generic Mapping Tools (GMT)
          version 3.2 Technical Reference & Cookbook, SOEST/NOAA.
          Wessel, P., and W. H. F. Smith, 1998, New, Improved Version of Generic
          Mapping Tools Released, EOS Trans., AGU, 79 (47), p. 579.
          Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic
          Mapping Tools Released, EOS Trans., AGU, 76 (33), p. 329.
          Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic
          Mapping Tools Released, http://www.agu.org/eos_elec/95154e.html,
          Copyright 1995 by the American Geophysical Union.
          Wessel, P., and W. H. F. Smith, 1991, Free Software Helps Map and
          Display Data, EOS Trans., AGU, 72 (41), p. 441.