<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<!--Converted with LaTeX2HTML 2002-2-1 (1.71)
original version by: Nikos Drakos, CBLU, University of Leeds
* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan
* with significant contributions from:
Jens Lippmann, Marek Rouchal, Martin Wilck and others -->
<HTML>
<HEAD>
<TITLE>1.4.5 Orthographic projection</TITLE>
<META NAME="description" CONTENT="1.4.5 Orthographic projection">
<META NAME="keywords" CONTENT="GMT_Tutorial">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1">
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
<LINK REL="STYLESHEET" HREF="GMT_Tutorial.css">
<LINK REL="next" HREF="node31.html">
<LINK REL="previous" HREF="node27.html">
<LINK REL="up" HREF="node20.html">
<LINK REL="next" HREF="node30.html">
</HEAD>
<BODY bgcolor="#ffffff">
<!--Navigation Panel-->
<A NAME="tex2html798"
HREF="node30.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html792"
HREF="node20.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html786"
HREF="node28.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html794"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<A NAME="tex2html796"
HREF="node63.html">
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html799"
HREF="node30.html">1.4.5.1 Exercises</A>
<B> Up:</B> <A NAME="tex2html793"
HREF="node20.html">1.4 Laboratory Exercises</A>
<B> Previous:</B> <A NAME="tex2html787"
HREF="node28.html">1.4.4.1 Exercises</A>
<B> <A NAME="tex2html795"
HREF="node1.html">Contents</A></B>
<B> <A NAME="tex2html797"
HREF="node63.html">Index</A></B>
<BR>
<BR>
<!--End of Navigation Panel-->
<H2><A NAME="SECTION00345000000000000000">
1.4.5 Orthographic projection</A>
</H2>
<A NAME="1559"></A>
<A NAME="590"></A>
<P>
The azimuthal orthographic projection (<B>-JG</B>) is one of several
projections with similar syntax and behavior; the one we have
chosen mimics viewing the Earth from space at an infinite distance;
it is neither conformal nor equal-area.
The syntax for this projection is
<BR>
<P>
<B>-JG</B><!-- MATH
$lon_0/lat_0/width$
-->
<IMG
WIDTH="109" HEIGHT="31" ALIGN="MIDDLE" BORDER="0"
SRC="img12.png"
ALT="$lon_0/lat_0/width$">
<BR>
<P>
where (<IMG
WIDTH="62" HEIGHT="29" ALIGN="MIDDLE" BORDER="0"
SRC="img10.png"
ALT="$lon_0, lat_0$">) is the center of the map (projection).
As an example we will try
<P>
<PRE>
pscoast -R0/360/-90/90 -JG280/30/6i -Bg30/g15 -Dc -A5000 -Gwhite \
-SDarkTurquoise -P > map.ps
</PRE>
<P>
<BR><HR>
<!--Table of Child-Links-->
<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></A>
<UL>
<LI><A NAME="tex2html800"
HREF="node30.html">1.4.5.1 Exercises</A>
</UL>
<!--End of Table of Child-Links-->
<HR>
<!--Navigation Panel-->
<A NAME="tex2html798"
HREF="node30.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html792"
HREF="node20.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html786"
HREF="node28.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html794"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<A NAME="tex2html796"
HREF="node63.html">
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html799"
HREF="node30.html">1.4.5.1 Exercises</A>
<B> Up:</B> <A NAME="tex2html793"
HREF="node20.html">1.4 Laboratory Exercises</A>
<B> Previous:</B> <A NAME="tex2html787"
HREF="node28.html">1.4.4.1 Exercises</A>
<B> <A NAME="tex2html795"
HREF="node1.html">Contents</A></B>
<B> <A NAME="tex2html797"
HREF="node63.html">Index</A></B>
<!--End of Navigation Panel-->
<ADDRESS>
Paul Wessel
2010-01-14
</ADDRESS>
</BODY>
</HTML>
