[OSRS-PROJ] Great Circle Mapping

Karl Swartz karl at kls2.com
Wed Apr 3 00:01:59 EST 2002

> Karl Swartz has let me know of his Great Circle Mapping web site - primarily
> for airport to airport flightlines I believe.  It is apparently built on parts
> of PROJ.4 (including the geodesic support?).
>    http://gc.kls2.com/

Hi all!  Yes, depicting flight paths was the original purpose for the
site, though it has accumulated lots of other uses since then.  The only
piece of PROJ.4 which I use is geod.  The online portion of the web
site uses it in three places -- the mapper portion uses it to compute
flight paths between locations and to compute points for ranges, while
the piece which generates the HTML wrapper uses geod to compute
distances for each path.  In addition, there's an offline use of geod in
the generation of ETOPS points, basically ranges around a large number
of alternate airports.  (See the site's FAQ if you want to know what
ETOPS is.)

It's been a very popular site since its debut in 1995, and February was
the first month in which over 100,000 maps were served.  Amongst other
uses, I'm told that people at Boeing use it in their work -- they have
internal tools which do essentially the same thing, but it's far easier
just to use my web site!

Anyway, if I hadn't found PROJ.4, it would have been a lot harder to
build, and I might never have done it.  I'm glad that PROJ.4 is still
being maintained -- it's a great little set of tools.

Karl Swartz	|Home	karl at kls2.com		http://www.kls2.com/~karl/
		|Work	karl at quartetns.com	http://www.quartetns.com/
"The average dog is a nicer person than the average person."
  - Andrew A. Rooney
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