NAME

       pssegy - Plot a SEGY file on a map

SYNOPSIS

       pssegy  SEGYfile  parameters region deviation [color] [ clip ] [ error ] [  ] [  ] [ nsamp ] [ ntrace ] [
       ] [  ] [  ] [ <mode><value> ] [ header ] [ filename ] [ [just/dx/dy/][c|label] ] [ [level] ] [ x_offset ]
       [ y_offset ] [ -p<flags> ] [ -t<transp> ]

       Note: No space is allowed between the option flag and the associated arguments.

DESCRIPTION

       pssegy reads a native (IEEE) format SEGY file and produces a PostScript image of the  seismic  data.  The
       imagemask  operator  is  used  so  that  the  seismic data are plotted as a 1-bit deep bitmap in a single
       (user-specified) color or gray shade, with a transparent background. The bitmap resolution is taken  from
       the  current GMT defaults. The seismic traces may be plotted at their true locations using information in
       the trace headers (in which case order of the traces in  the  file  is  not  significant).  Standard  GMT
       geometry routines are used so that in principle any map projection may be used, however it is likely that
       the  geographic  projections  will  lead  to  unexpected  results.  Beware also that some parameters have
       non-standard meanings.

       Note   that   the   order    of    operations    before    the    seismic    data    are    plotted    is
       deviation*[clip]([bias]+[normalize](sample  value)). Deviation determines how far in the plot coordinates
       a [normalized][biased][clipped] sample value of 1 plots from the trace location.

       The SEGY file should be a disk image of the tape format (i.e., 3200 byte text header, which  is  ignored,
       400 byte binary reel header, and 240 byte header for each trace) with samples as native real*4 (IEEE real
       on all the platforms to which I have access).

REQUIRED ARGUMENTS

       SEGYfile
              Seismic SEGY data set to be imaged.

       -Jparameters (more ...)
              Select map projection.

       -R[unit]west/east/south/north[/zmin/zmax][r]
              west,  east,  south, and north specify the region of interest, and you may specify them in decimal
              degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if  lower  left  and  upper  right  map
              coordinates  are  given instead of w/e/s/n. The two shorthands -Rg and -Rd stand for global domain
              (0/360 and -180/+180 in longitude respectively, with -90/+90 in latitude).  Alternatively for grid
              creation, give Rcodelon/lat/nx/ny, where code is a 2-character combination of L, C, R  (for  left,
              center, or right) and T, M, B for top, middle, or bottom. e.g., BL for lower left.  This indicates
              which  point  on a rectangular region the lon/lat coordinate refers to, and the grid dimensions nx
              and ny with grid spacings via -I is used  to  create  the  corresponding  region.   Alternatively,
              specify  the  name  of an existing grid file and the -R settings (and grid spacing, if applicable)
              are copied from the grid. Using -Runit expects projected (Cartesian) coordinates  compatible  with
              chosen  -J  and  we  inversely  project  to  determine  actual rectangular geographic region.  For
              perspective view (-p), optionally append /zmin/zmax.  In case of perspective view (-p), a  z-range
              (zmin,  zmax)  can  be  appended  to indicate the third dimension. This needs to be done only when
              using the -Jz option, not when using only the -p option. In the latter case a perspective view  of
              the plane is plotted, with no third dimension.

       -Ddeviation
              gives the deviation in X units of the plot for 1.0 on the scaled trace.

       -F[color]
              Fill  trace  (variable  area,  defaults  to  filling  positive).  Specify the color with which the
              imagemask is filled.

       -W     Draw wiggle trace.

       You must specify at least one of -W and -F.

OPTIONAL ARGUMENTS

       -A     Flip the default byte-swap state (default assumes data have a bigendian byte-order).

       -Cclip Sample value at which to clip data (clipping is applied to both positive and negative values).

       -Eerror
              Allow error difference between requested and actual trace locations when using -T option.

       -I     Fill negative rather than positive excursions.

       -K (more ...)
              Do not finalize the PostScript plot.

       -L     Override number of samples per trace in reel header  (program  attempts  to  determine  number  of
              samples from each trace header if possible to allow for variable length traces).

       -M     Override  number  of  traces  specified  in  reel header. Program detects end of file (relatively)
              gracefully, but this parameter limits number of traces that the program attempts to read.

       -N     Normalize trace by dividing by rms amplitude over full trace length.

       -O (more ...)
              Append to existing PostScript plot.

       -P (more ...)
              Select "Portrait" plot orientation.

       -Q<mode><value>

              Can be used to change 5 different settings depending on mode:
                     -Qbbias to bias scaled traces (-Qb-0.1 subtracts 0.1 from values).

                     -Qidpi sets the dots-per-inch resolution of the image [300].

                     -Quredvel to apply reduction velocity (negative value removes reduction already present).

                     -Qxmult to multiply trace locations by mult.

                     -Qydy to override sample interval in SEGY reel header.

       -Sheader
              Read trace locations from trace headers: header is either c for CDP, o for offset, or bnum to read
              a long starting at byte num in the header (first  byte  corresponds  to  num  =  0).  Default  has
              location given by trace number.

       -Tfilename
              Plot only traces whose location corresponds to a list given in filename. Order in which traces are
              listed is not significant - the entire space is checked for each trace.

       -U[just/dx/dy/][c|label] (more ...)
              Draw GMT time stamp logo on plot.

       -V[level] (more ...)
              Select verbosity level [c].

       -X[a|c|f|r][x-shift[u]]

       -Y[a|c|f|r][y-shift[u]] (more ...)
              Shift plot origin.

       -Z     Do not plot traces with zero rms amplitude.

       -p[x|y|z]azim/elev[/zlevel][+wlon0/lat0[/z0]][+vx0/y0] (more ...)
              Select perspective view.

       -t[transp] (more ...)
              Set PDF transparency level in percent.

       -^ or just -
              Print a short message about the syntax of the command, then exits (NOTE: on Windows use just -).

       -+ or just +
              Print  an  extensive usage (help) message, including the explanation of any module-specific option
              (but not the GMT common options), then exits.

       -? or no arguments
              Print a complete usage (help) message, including the explanation of options, then exits.

       --version
              Print GMT version and exit.

       --show-datadir
              Print full path to GMT share directory and exit.

EXAMPLES

       To plot the SEGY file wa1.segy with normalized traces plotted at true offset locations,  clipped  at  +-3
       and with wiggle trace and positive variable area shading in black, use

              gmt pssegy wa1.segy -JX5i/-5i -R0/100/0/10 -D1 -C3 -N -So -W -Fblack > segy.ps

       To  plot  the  SEGY  file wa1.segy with traces plotted at true cdp*0.1, clipped at +/-3, with bias -1 and
       negative variable area shaded red, use

              gmt pssegy wa1.segy -JX5i/-5i -R0/100/0/10 -D1 -C3 -Sc -Qx0.1 -Fred -Qb-1 -I > segy.ps

SEE ALSO

       gmt, pssegyz, segy2grd

COPYRIGHT

       2015, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe

5.2.1                                           January 28, 2016                                    PSSEGY(1gmt)