1PSSEGYZ(1) Generic Mapping Tools PSSEGYZ(1)
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6 pssegyz - Create imagemasked postscript from SEGY file
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9 pssegyz SEGYfile -Jparameters -Jz|Zparameters
10 -Rwest/east/south/north[/zmin/zmax][r] -Ddeviation -F[rgb|gray]|-W [
11 -Bbias ] [ -Cclip ] [ -Eazimuth/elevation ] [ -I ] [ -K ] [ -Lnsamp ] [
12 -Mntrace ] [ -N ] [ -O ] [ -P ] [ -Sheader_x/header_y ] [ -Uredvel ] [
13 -V ] [ -Xscale ] [ -Ysample_int ] [ -Z ]
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16 pssegyz reads a native (IEEE) format SEGY file and produces a Post‐
17 Script image of the seismic data. The imagemask operator is used so
18 that the seismic data are plotted as a 1-bit deep bitmap in a single
19 (user-specified) color or gray shade, with a transparent background.
20 The bitmap resolution is taken from the current GMT defaults. The
21 seismic traces may be plotted at their true locations using information
22 in the trace headers (in which case order of the traces in the file is
23 not significant). Standard GMT geometry routines are used so that in
24 principle any map projection may be used, however it is likely that the
25 geographic projections will lead to unexpected results. Beware also
26 that some parameters have non-standard meanings, and a couple of the
27 options for pssegy are not available in pssegyz. Note that the order
28 of operations before the seismic data are plotted is devia‐
29 tion*[clip]([bias]+[normalize](sample value)). Deviation determines how
30 far in the plot coordinates a [normalized][biased][clipped] sample
31 value of 1 plots from the trace location. The SEGY file should be a
32 disk image of the tape format (ie 3200 byte text header, which is
33 ignored, 400 byte binary reel header, and 240 byte header for each
34 trace) with samples as native real*4 (IEEE real on all the platforms to
35 which I have access)
36 SEGYfile
38 Seismic data set to be imaged
39 -J Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or
41 width in UNIT (upper case modifier). UNIT is cm, inch, or m,
42 depending on the MEASURE_UNIT setting in .gmtdefaults4, but this
43 can be overridden on the command line by appending c, i, or m to
44 the scale/width value. When central meridian is optional,
45 default is center of longitude range on -R option. Default
46 standard parallel is the equator. For map height, max dimen‐
47 sion, or min dimension, append h, +, or - to the width, respec‐
48 tively.
49 More details can be found in the psbasemap man pages.
50 CYLINDRICAL PROJECTIONS:
52 -Jclon0/lat0/scale (Cassini)
54 -Jcyl_stere/[lon0/[lat0/]]scale (Cylindrical Stereographic)
55 -Jj[lon0/]scale (Miller)
56 -Jm[lon0/[lat0/]]scale (Mercator)
57 -Jmlon0/lat0/scale (Mercator - Give meridian and standard paral‐
58 lel)
59 -Jo[a]lon0/lat0/azimuth/scale (Oblique Mercator - point and
60 azimuth)
61 -Jo[b]lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
62 -Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and
63 pole)
64 -Jq[lon0/[lat0/]]scale (Cylindrical Equidistant)
65 -Jtlon0/[lat0/]scale (TM - Transverse Mercator)
66 -Juzone/scale (UTM - Universal Transverse Mercator)
67 -Jy[lon0/[lat0/]]scale (Cylindrical Equal-Area)
68 CONIC PROJECTIONS:
70 -Jblon0/lat0/lat1/lat2/scale (Albers)
72 -Jdlon0/lat0/lat1/lat2/scale (Conic Equidistant)
73 -Jllon0/lat0/lat1/lat2/scale (Lambert Conic Conformal)
74 AZIMUTHAL PROJECTIONS:
76 -Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area)
78 -Jelon0/lat0[/horizon]/scale (Azimuthal Equidistant)
79 -Jflon0/lat0[/horizon]/scale (Gnomonic)
80 -Jglon0/lat0[/horizon]/scale (Orthographic)
81 -Jglon0/lat0/altitude/azimuth/tilt/twist/Width/Height/scale
82 (General Perspective).
83 -Jslon0/lat0[/horizon][/slat]/scale (General Stereographic)
84 MISCELLANEOUS PROJECTIONS:
86 -Jh[lon0/]scale (Hammer)
88 -Ji[lon0/]scale (Sinusoidal)
89 -Jkf[lon0/]scale (Eckert IV)
90 -Jk[s][lon0/]scale (Eckert IV)
91 -Jn[lon0/]scale (Robinson)
92 -Jr[lon0/]scale (Winkel Tripel)
93 -Jv[lon0/]scale (Van der Grinten)
94 -Jw[lon0/]scale (Mollweide)
95 NON-GEOGRAPHICAL PROJECTIONS:
97 -Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
99 -Jxx-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log,
100 and power scaling)
101 -R west, east, south, and north specify the Region of interest, and
103 you may specify them in decimal degrees or in
104 [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and
105 upper right map coordinates are given instead of w/e/s/n. The
106 two shorthands -Rg and -Rd stand for global domain (0/360 and
107 -180/+180 in longitude respectively, with -90/+90 in latitude).
108 -D gives the deviation in X units of the plot for 1.0 on the scaled
110 trace, This may be a single number (applied equally in X and Y
111 directions) or devX/devY
112 -E Azimuth and elevation for the 3-D projection.
114 -F[rgb|gray]
116 Fill trace (variable area, defaults to filling positive). rgb or
117 gray gives the color with which the imagemask is filled.
118 -W Draw wiggle trace.
120 You must specify at least one of -W and -F.
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124 No space between the option flag and the associated arguments.
125 -B Bias to apply to data (added to sample values).
127 -C Sample value at which to clip data (clipping is applied to both
129 positive and negative values).
130 -I Fill negative rather than positive excursions.
132 -K More PostScript code will be appended later [Default terminates
134 the plot system].
135 -L Override number of samples per trace in reel header (program
137 attempts to determine number of samples from each trace header
138 if possible to allow for variable length traces).
139 -M Override number of traces specified in reel header. Program
141 detects end of file (relatively) gracefully, but this parameter
142 limits number of traces that the program attempts to read.
143 -N Normalize trace by dividing by rms amplitude over full trace
145 length.
146 -O Selects Overlay plot mode [Default initializes a new plot sys‐
148 tem].
149 -P Selects Portrait plotting mode [Default is Landscape, see gmtde‐
151 faults to change this].
152 -S Read trace locations from trace headers: header is either c for
154 CDP, o for offset, b<num> to read a long starting at byte <num>
155 in the header (first byte corresponds to num=0), or a number to
156 fix the location.
157 First parameter for x, second for y. Default has X and Y given
158 by trace number.
159 -U Apply reduction velocity by shifting traces upwards by red‐
161 vel/|offset|. Negative velocity removes existing reduction.
162 Units should be consistent with offset in trace header and sam‐
163 ple interval.
164 -V Selects verbose mode, which will send progress reports to stderr
166 [Default runs "silently"].
167 -X Multiply trace locations by scale before plotting.
169 -Y Override sample interval in reel header.
171 -Z Do not plot traces with zero rms amplitude.
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176 To plot the SEGY file wa1.segy with normalized traces plotted at true
177 offset locations, clipped at +-3 and with wiggle trace and positive
178 variable area shading in black, use
179 pssegyz wa1.segy -JX5/-5 -D1 -Jz0.05 -E180/5 -R0/100/0/10/0/10 -C3 -N
181 -So -W -Fblack > segy.ps
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184 Variable area involves filling four-sided figures of distressing gener‐
185 ality. I know that some of the more complex degenerate cases are not
186 dealt with correctly or at all; the incidence of such cases increases
187 as viewing angles become more oblique, and particularly as the viewing
188 elevation increases. Wiggle-trace plotting is not affected.
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191 GMT(1), pssegy(1)
192GMT 4.3.1 15 May 2008 PSSEGYZ(1)