[OSRS-PROJ] Re: On the Ellipsoidal Transverse Mercator

Gerald I. Evenden gerald.evenden at verizon.net
Wed Oct 15 21:40:58 EDT 2003

Please accept my most humble appologies for being such a plebean amid
the great minds of cartography.  It must greatly pain you that I dare mingle
amongst this august group and insult them with such impertinent and
ignorant questions.

My true appologies go to other readers of this group and my failure to
keep this "discussion" between Strebe and myself private.  There is obviously
a great deal of "tension" between us.  I was trying to learn something and
obtain pertinent information and I have obviously failed.

Sorry.  Please, let's drop the subject.
On Wednesday 15 October 2003 03:00 pm, Strebe at aol.com wrote:
> Gerald Evenden <gerald.evenden at verizon.net> writes:
> > A question here, are we talking about the Gauss-Kruger model or some
> > other construct?  Dozier, Lee are dealing with the Gauss-Kruger model.
> There is no other construct. If the projection maps the ellipsoid
> conformally such that the central meridian everywhere is unity, and the map
> is not interrupted along the central meridian, then the map is the
> ellipsoidal transverse Mercator = Gauss Kruger. All methods yield the same
> results if they are pursued with unbounded accuracy. That is true of any
> conformal projection: if you supply a boundary condition, then you have
> specified the entire conformal map.
> > The description below contains exotic concepts and lacks sufficent
> > detail for review.  Without detailed, published description it remains
> > an unfounded claim.
> No, Mr. Evenden, the description is complete and mundane. Anyone who
> understands both the transverse Mercator and complex analysis would
> recognize it as a legitimate path to the ellipsoidal transverse Mercator.
> Your insecure insistence upon a published description is your loss, not
> mine; I and probably many other people reading this list are perfectly
> capable of generating correct maps with it. I have wheedled Wallis to
> publish. It's none of my concern if he does not and it is not my place to
> publish his method. I'm afraid you'll have to waffle through Dozier's
> account, since the best I can supply is references to Snyder, Dozier, and
> Lee, Dr. Wallis's name and location, source code, distortion analyses,
> comparisons with UTM coordinates, and images.
> > Dr. Wallis claims that the publication of his transverse mercator
> > is pending.
> It will be awhile, he has told me, since it seems what he is writing is a
> book that goes far beyond just a method for generating the ellipsoidal
> transverse Mercator. It would not satisfy you anyway, since I do not expect
> it will be peer-reviewed.
> > Apparently the map is segmented.
> It is not segmented. Two tombstones meet foot-to-foot, and two sets of such
> conjoined tombstones meet side-by-side. The tombstone shape is the
> classical simple rectangle with one end rounded as a semicircle.
> > Note: Wallis only refers to mapping the N -or- S hemispheres
> > whereas general concept of TM has no difficulty in the N-S
> > direction but rather in the E-W direction.
> Bizarre interpretation. Wallis clearly states that the entire north or
> south hemisphere is mapped. He's not talking about "direction"; he's
> talking about the extent of the map. The spherical transverse Mercator
> cannot map the entire north or south hemisphere.
> > BTW: is there a plotted example of this version of the transverse
> > mercator available on the web somewhere?
> No, but if someone were to supply a place to deposit it, I would be happy
> to supply some. I can't imagine why you would be interested in pictures of
> unfounded claims, though. And there is no such thing as "this version"; all
> transverse Mercators are the same.
> All who might be interested and don't find themselves consumed by
> pathological skepticism, or who understand the method and therefore have no
> need for skepticism, feel free to contact me with questions.
> Regards,
> daan Strebe
> Geocart author
> <A HREF="http://www.mapthematics.com">http://www.mapthematics.com</A>

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