Subject:
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Re: twisted map
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Newsgroups:
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lugnet.off-topic.geek
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Date:
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Mon, 3 Jun 2002 19:10:27 GMT
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Viewed:
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2365 times
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In lugnet.off-topic.geek, Dan Boger writes:
> In lugnet.off-topic.geek, Suzanne D. Rich writes:
> > Found this while looking for new LUG map graphics last night..
> >
> > http://www.lib.utexas.edu/maps/cia01/world_sm01.jpg
> >
> > I'd never seen a projection like this before. Anyone know about them?
> > This one's from the CIA.
> >
> > Uh oh, it's happening again... [mesmerized] can't.. stop.. staring at
> > it.. must.. print out.. for office wall.
>
> looks like "Oblique Mercator" from:
>
> http://mac.usgs.gov/mac/isb/pubs/MapProjections/projections.html
>
> but only kinda-sorta...
It's a transverse projection, probably at 45º of rotation--it looks
like a Lambert, but without access to my Bugayevsky and Snyder [1] I
couldn't tell you what the exact variation is called. There are so
many names for so many slight variations of the mathematics that I
can't remember them all (and besides, my work usually involves UTM
and little else). But it was definitely rotated transversally before
the projection was calculated--that's the only way to get output
quite like that.
For general information on transverse projections, see this:
http://www.mapthematics.com/Essentials/Essentials.html
best
LFB
[1] L. Bugayevsky and J. Snyder, _Map Projections: A Reference Manual_.
London: Francis & Taylor, 1995.
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Message has 1 Reply:
 | | Re: twisted map
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| (...) I agree with your assessment that it is a transverse project, but I thought Lambert was only suitable for projections of a hemisphere? I could be mistaken though, it's been several years since I worried about projections and never did much (...) (24 years ago, 5-Jun-02, to lugnet.off-topic.geek)
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