[Proj] Re: Graduated equidistant projections for convenient co-ordinate transformations

Gerald I. Evenden geraldi.evenden at gmail.com
Mon Aug 6 07:54:20 PDT 2007


On Monday 06 August 2007 8:37 am, strebe at aol.com wrote:
>  Michael,
>
> I am not here to crush your soul. You seem a good deal more knowledgeable
> and interested in map projections than most, which I'm happy to see and
> certainly want to encourage.
>
> On the other hand, your jargon is idiosyncratic and your analysis of the
> issues surrounding your thesis seem to evolve as we talk. These make it
> hard for me to engage you in conversation. When a person wishes to announce
> that the world ought to be doing things differently, then it behooves the
> person to exercise due diligence. That includes a rigorous analysis and
> vocabulary of the domain. Without both, conversation gets distracted by the
> parties involved just trying to figure out what the other is saying.
>
I could not agree more.
>
> Since I'm the only other one participating in this discussion I have to
> think everyone else is long bored of it. (It's also probably off-topic by
> some people's assessment.) I'm not going to address each of your points. As
> an illustration of talking past each other in your latest post:

I have resisted adding to this thread up until now because of the rather long 
winded emails that make short, to the point comments difficult.  Against my 
better judgement I will make a short summary of my position on some aspects 
of the thread:

1. In distributing raw data (numeric information) itself I feel using a map as 
the transfer media very questionable.  It would seem to me that the 
information should be made available in some data base format such as an 
arc-node system or at least as point values in a flat file.

The only times I have been involved with digitizing information from maps was 
when the data was originally plotted on the map (as in field operations), 
information was manual drafted on the map (various contourings) and when 
there was absolutely no other way to get hold of the information.

I might add, that digitizing a map can be performed without having any idea of 
the projection by using a callibration grid and correction polynomials.  
This, of course, most easily applies to large scale maps.

2. In displaying global data I feel there is no perfect projection but I must 
add that an equal area projection provides the best mode for visual 
understanding of the what the data represents.

3. In regards to the sinusoidal projection, I think it is one of the poorer 
projections unless it is used in its interupted form.  If it is in interupted 
form, digitizing data from such a map would be a control monster.

-- 
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939)  British psychologist



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