pssolar - Plot day-light terminators and other sunlight
parameters
pssolar [ -B[p|s]parameters ] [
-C ] [ -Gfill|c ] [
-I[lon/lat][+ddate][+zTZ] ] [
-Jparameters ] [ -K ] [ -M ] [ -N ] [
-O ] [ -P ] [ -Q ] [ -Rregion ] [
-Tdcna[+ddate][+zTZ]] [
-U[stamp] ] [ -V[level] ] [ -Wpen
] [ -Xx_offset ] [ -Yy_offset ] [
-bobinary ] [ -hheaders ] [ -oflags ] [ -pflags
] [ -ttransp ]
Note: No space is allowed between the option flag and the
associated arguments.
pssolar Calculate and plot the day-night terminator and the
civil, nautical and astronomical twilights.
There are no required arguments but either -I or -T
must be selected.
- -C
- Formats the report selected by -I using tab-separated fields on a
single line. The output is Sun Lon Lat Azimuth Elevation in
degrees, Sunrise Sunset Noon in decimal days, day length in
minutes, SolarElevationCorrected corrected for the effect of
refraction index and Equation of time in minutes. Note that if no
position is provided in -Ilon/lat the data after
Elevation refers to the point (0,0).
- -Gfill|c
- Select color or pattern for filling of terminators; or use -Gc for
clipping [Default is no fill]. Deactivate clipping by appending the output
of gmt psclip -C.
- -I[lon/lat][+ddate][+zTZ]
- Print current sun position as well as Azimuth and Elevation. Append
lon/lat to print also the times of Sunrise, Sunset, Noon and length of the
day. Add +ddate in ISO format, e.g,
+d2000-04-25, to compute sun parameters for this date. If
necessary, append time zone via +zTZ.
- -M
- Write terminator(s) as a multisegment ASCII (or binary, see
-bo) file to standard output. No plotting occurs.
- -N
- Invert the sense of what is inside and outside the terminator. Only used
with clipping (-Gc) and cannot be used together with
-B.
- -Tdcna[+ddate][+zTZ]
- Plot (or dump; see -M) one or more terminators defined via the
dcna flags. Where: d means day/night terminator; c
means civil twilight; n means nautical twilight; a means
astronomical twilight. Add +ddate in ISO format, e.g,
+d2000-04-25T12:15:00 to know where the day-night was at
that date. If necessary, append time zone via +zTZ.
- -W[-|+][pen]
(more ...)
- Set pen attributes for lines or the outline of symbols [Defaults: width =
default, color = black, style = solid].
-X[a|c|f|r][x-shift[u]]
Print current Sun position and Sunrise, Sunset times at:
gmt pssolar -I-7.93/37.079+d2016-02-04T10:01:00
Plot the day-night and civil twilight
gmt pscoast -Rd -W0.1p -JQ0/14c -Ba -BWSen -Dl -A1000 -P -K > terminator.ps
gmt pssolar -R -J -W1p -Tdc -O >> terminator.ps
Set up a clip path overlay based on the day/night terminator:
gmt pssolar -R -J -Gc -Tc -O -K >> someplot.ps
gmt, psclip, pscoast, psxy
2019, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F.
Wobbe