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Subject: 
Re: twisted map
Newsgroups: 
lugnet.off-topic.geek
Date: 
Wed, 5 Jun 2002 12:55:02 GMT
Viewed: 
453 times
  
Mr L F Braun wrote:
   For hemispheric mapping, conic projections were generally used.
   Lambert can be applied cylindrically, though:

   http://aips2.nrao.edu/docs/memos/107/node3.html#SECTION00031300000000000000

   Which gives the map severe t/b end compression.  I'm not sure, again,
   what the maths are that govern the original map Suz put up.  There
   are so many small variations of equal-area projections that I just
   went with Lambert as being one of the best-known.

   Of course the UTM is nice to use when you're anywhere near the equator.
   Most of my work involving equatorial Africa (<10° N/S) therefore uses
   it.

Changing topics slightly, what are currently doing with mapping?  Is it
part of your graduate work?  just curious...  I've been doing a lot of
current work with UTM and Stateplane in the past few months.

   I deal with the history of cartography, specifically the history of
   geodesy in Africa (arc of the 30th Meridian).  In a sense projections
   don't come into play except as authorities were concerned with the
   computations and adjustments of the Arc for UTM projection use.  The
   arc, of course, was the provider of the primary datum used--it was
   even a reference source for Hartebeesthoek94 and (IIRC) WGS84.

   So I don't deal with map projections directly--I deal with the data
   that are fed through the projection maths to get the maps.  I'm heading
   to SA on a Fulbright in October to get the African angle of this map
   rendering--it should be very interesting.

cool.  very cool.

   I constantly learn more and more about cartography and surveying.  It's
   fun--I actually know how to use an 18th-C. theodolite now!

cool, i would occasionally go down to the museum at the USGS HQ in
Virginia and examine the collection of historical survey devices.

   What do you do?

Well, I first started work with mapping when I spent two years providing
Geographic Information Systems (GIS) support for the Climate History
program of the USGS.  There I mostly was involved in producing products
involved with selecting deep ocean sediment cores to examine as part of
an effort to describe Pleistocene and Early Holocene changes in climate
in North America around the Gulf of Mexico (althought I did do some
small projects in both the Arctic and Antarctic).

Currently, I'm a conservation biology grad student, using GIS techniques
as part of a project to correlate environmental variables and history
with plant success in a fire controlled ecosystem.  Most basemap data
for this project typically comes in State Plane or UTM projections and I
typically reproject the stateplane maps to UTM (zone 17- northwestern
oh).  it's a rather small area to work with overalll, about 20x30 km.
So in short I don't do all that much with projections anymore, but it is
a fascinating subject.

As a side project, I've been working (or is that nonworking?(1)) on some
contributions for a zine(2) about  "amatuer cartography".  It's going to
be a collection of maps people make to describe their local
neighborhood.  I don't think there is going to any serious surveying
contained within it.  So far there have been some amazing
contributions-- a map of a punk house and everyone who ever lived there
over a number of years- in scroll form, a overally detailed map of a
somehouse including placement of nick-knacks arounf the house, small
direction maps scribbled on scraps of paper that he found lying on the
street. It's going to be amazing.

-chris



Message has 1 Reply:
  Re: twisted map
 
<snip> Christopher Tracey <ctracey@enviroweb.org> schrieb in im Newsbeitrag: 3CFE0A26.C0A7C942@en...web.org... <snip> (...) <snip> oh do provide more info on that little side project of yours, maybe on a little site of it's own? it really sounds (...) (22 years ago, 8-Jun-02, to lugnet.off-topic.geek)

Message is in Reply To:
  Re: twisted map
 
(...) For hemispheric mapping, conic projections were generally used. Lambert can be applied cylindrically, though: (URL) Which gives the map severe t/b end compression. I'm not sure, again, what the maths are that govern the original map Suz put (...) (22 years ago, 5-Jun-02, to lugnet.off-topic.geek)

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