Provided by: gmt_4.5.11-1build1_amd64 
NAME
pssegyz - Create imagemasked postscript from SEGY file
SYNOPSIS
pssegyz SEGYfile -Jparameters -Jz|Zparameters -Rwest/east/south/north[/zmin/zmax][r]
-Ddeviation -F[rgb|gray]|-W [ -Bbias ] [ -Cclip ] [ -Eazim/elev[+wlon/lat[/z]][+vx0/y0] ]
[ -I ] [ -K ] [ -Lnsamp ] [ -Mntrace ] [ -N ] [ -O ] [ -P ] [ -Sheader_x/header_y ] [
-Uredvel ] [ -V ] [ -Xscale ] [ -Ysample_int ] [ -Z ]
DESCRIPTION
pssegyz 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, and a couple of the options for pssegy are not
available in pssegyz. 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 (ie 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)
SEGYfile
Seismic data set to be imaged
-J Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or width in UNIT (upper
case modifier). UNIT is cm, inch, or m, depending on the MEASURE_UNIT setting in
.gmtdefaults4, but this can be overridden on the command line by appending c, i, or
m to the scale/width value. When central meridian is optional, default is center
of longitude range on -R option. Default standard parallel is the equator. For
map height, max dimension, or min dimension, append h, +, or - to the width,
respectively.
More details can be found in the psbasemap man pages.
CYLINDRICAL PROJECTIONS:
-Jclon0/lat0/scale (Cassini)
-Jcyl_stere/[lon0/[lat0/]]scale (Cylindrical Stereographic)
-Jj[lon0/]scale (Miller)
-Jm[lon0/[lat0/]]scale (Mercator)
-Jmlon0/lat0/scale (Mercator - Give meridian and standard parallel)
-Jo[a]lon0/lat0/azimuth/scale (Oblique Mercator - point and azimuth)
-Jo[b]lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
-Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and pole)
-Jq[lon0/[lat0/]]scale (Cylindrical Equidistant)
-Jtlon0/[lat0/]scale (TM - Transverse Mercator)
-Juzone/scale (UTM - Universal Transverse Mercator)
-Jy[lon0/[lat0/]]scale (Cylindrical Equal-Area)
CONIC PROJECTIONS:
-Jblon0/lat0/lat1/lat2/scale (Albers)
-Jdlon0/lat0/lat1/lat2/scale (Conic Equidistant)
-Jllon0/lat0/lat1/lat2/scale (Lambert Conic Conformal)
-Jpoly/[lon0/[lat0/]]scale ((American) Polyconic)
AZIMUTHAL PROJECTIONS:
-Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area)
-Jelon0/lat0[/horizon]/scale (Azimuthal Equidistant)
-Jflon0/lat0[/horizon]/scale (Gnomonic)
-Jglon0/lat0[/horizon]/scale (Orthographic)
-Jglon0/lat0/altitude/azimuth/tilt/twist/Width/Height/scale (General Perspective).
-Jslon0/lat0[/horizon]/scale (General Stereographic)
MISCELLANEOUS PROJECTIONS:
-Jh[lon0/]scale (Hammer)
-Ji[lon0/]scale (Sinusoidal)
-Jkf[lon0/]scale (Eckert IV)
-Jk[s][lon0/]scale (Eckert VI)
-Jn[lon0/]scale (Robinson)
-Jr[lon0/]scale (Winkel Tripel)
-Jv[lon0/]scale (Van der Grinten)
-Jw[lon0/]scale (Mollweide)
NON-GEOGRAPHICAL PROJECTIONS:
-Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
-Jxx-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log, and power scaling)
-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, specify the name of an
existing grid file and the -R settings (and grid spacing, if applicable) are copied
from the grid.
-D gives the deviation in X units of the plot for 1.0 on the scaled trace, This may be
a single number (applied equally in X and Y directions) or devX/devY
-E Sets the viewpoint's azimuth and elevation (for perspective view) [180/90]. For
frames used for animation, you may want to append + to fix the center of your data
domain (or specify a particular world coordinate point with +wlon0/lat[/z]) which
will project to the center of your page size (or specify the coordinates of the
projected view point with +vx0/y0).
-F[rgb|gray]
Fill trace (variable area, defaults to filling positive). rgb or gray gives the
color with which the imagemask is filled.
-W Draw wiggle trace.
You must specify at least one of -W and -F.
OPTIONS
No space between the option flag and the associated arguments.
-A Flip the default byte-swap state (default assumes data have a bigendian byte-
order).
-B Bias to apply to data (added to sample values).
-C Sample value at which to clip data (clipping is applied to both positive and
negative values).
-I Fill negative rather than positive excursions.
-K More PostScript code will be appended later [Default terminates the plot system].
-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 Selects Overlay plot mode [Default initializes a new plot system].
-P Selects Portrait plotting mode [Default is Landscape, see gmtdefaults to change
this].
-S Read trace locations from trace headers: header is either c for CDP, o for offset,
b<num> to read a long starting at byte <num> in the header (first byte corresponds
to num=0), or a number to fix the location.
First parameter for x, second for y. Default has X and Y given by trace number.
-U Apply reduction velocity by shifting traces upwards by redvel/|offset|. Negative
velocity removes existing reduction. Units should be consistent with offset in
trace header and sample interval.
-V Selects verbose mode, which will send progress reports to stderr [Default runs
"silently"].
-X Multiply trace locations by scale before plotting.
-Y Override sample interval in reel header.
-Z Do not plot traces with zero rms amplitude.
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
pssegyz wa1.segy -JX 5/-5 -D 1 -Jz 0.05 -E 180/5 -R 0/100/0/10/0/10 -C 3 -N -S o -W -F
black > segy.ps
BUGS
Variable area involves filling four-sided figures of distressing generality. I know that
some of the more complex degenerate cases are not dealt with correctly or at all; the
incidence of such cases increases as viewing angles become more oblique, and particularly
as the viewing elevation increases. Wiggle-trace plotting is not affected.
SEE ALSO
GMT(1), pssegy(1)