[Proj] Graduated equidistant has a name. Another projection
mikeo2106 at msn.com
Mon Aug 13 17:28:20 EDT 2007
Your "equidistant elliptical" is Apianus II.
Yes, Id have been very surprised if someone hadnt previously suggested
that obvious and simply-constructed projection.
Your "graduated equidistant"
doesn't really have a name;
Actually it does have a name. Its called the graduated equidistant
(cylindrical, conic or azimuthal) projection. The one I recommend is the
graduated equidistant cylindrical because it possesses the linearly
interpolable positions property (LIPP).
Perhaps what Daan meant to say was that it didnt have a name before I named
it's just the equirectangular projection with
standard parallel set to need.
and the Lambert-Lagrange projection is just a use of the Mercator and the
stereographic. Yes, the graduated equidistant projections are more obvious
and simpler in their construction, but they are distinct projections in
their own right, though they use equidistant projections. They have a
specific rule for setting the north-south scale in each latitude-band. For a
world map, Ive suggested a 10 degree graticule and latitude band.
And, for instance, the graduated equidistant cylindrical closely resembles
Mercator, probably to the point of being difficult to distinguish from it
without measurement. As I said, it can be regarded as the beginning of an
approximation to the Mercator.
Should the graduated equidistant projections have a name? Yes, anything
useful should have a name. Those projections, like Apianus II, are obvious
and simply constructed. Id be surprised if they havent been proposed &/or
used in the past. Their simplicity and usefulness (especially the
cylindrical) certainly justify their having a name.
Lastly, I concur in commending Daan for his patience in this exchange. For
in continuing to try to talk to someone whose positions were evolving so
inconsistently that he actually suggested an equal-area compromise when Daan
claimed that equal area is a necessary attribute for a data map. To quote
Daan, it doesnt get any muddier than that. And try to imagine Daans
exasperation with someone who was so dishonest or negligent that he even
mistakenly claimed that he suggested the equal-area compromise in his first
posting, when actually it was in his second posting, immediately after Daan
advocated the need for equal-area.
Obviously the inconsistent evolution described above is enough to render
communication impossible, and so yes, commendations to you, Daan.
Id like to suggest another obvious and simply-constructed projection, one
that has probably been proposed before:
In the manner of the Aitoff and Aitoff-Hammer projections, start with an
orthographic map of half of the Earth, in equatorial aspect. Expand it
east-west to twice its width, resulting in a 2:1 elliptical map. Re-label
its meridians so that they nominally extend over the Earths entire
circumferance. As with similar maps, the central meridian should be the
Greenwich meridian, or somewhere around the Europes west coast, for
This results in an orthographic view of a 2:1 oblate ellipsoid on one side
of which the Earths surface has been copied.
Like the other projections Ive suggested, the map is so simply-constructed
that its construction can be explained to anyone. I consider that an
important property that seems little valued by cartographers. In this case,
of course, the orthographics graphical construction is used in that
For an uninterrupted world map, it shows an especially realistic-looking and
attractive portrayal of the Earth.
Like the ordinary orthographic, t doesnt do a good job of showing areas
near its edges.
It probably already has a name, but for now Id call it orthographic
elliptical or elliptical orthographic.
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