Re: Coordinate Systems Proposals

Brian Eaton (eaton@merlin.cgd.ucar.EDU)
Tue, 15 Jul 1997 09:32:48 -0600 (MDT)

Hi John,

> > 
> > Your question is really about how to interpret the coordinates.  The same
> 
> Actually, my question was more fundamental than an interpretation of
> the coordinates.  (I can wire in a projection module later if I want to
> display the data on a globe.)  At first, I usually just render the data
> in a cartesian "box".  That is, I'm willing to take the lat's and lon's
> and just treat them as "distances" along 2 axes, but I would like the
> visualization to reflect the fact that, eg, the lon and lat spacing
> differ, so that I can get something close to a "correct" aspect ratio.
> What's the rule that tell me that lat(2,3) is the y-axis coordinate for
> temp(2,3)?

When you refer to a "correct" aspect ratio aren't you talking about an
interpretation issue?  You only know that a one degree lon spacing
corresponds to a smaller great circle distance the closer you get to the
pole because you are interpreting the coordinate as a longitude coordinate.
If you're not interested in that interpretation of the coordinate variable
then it seems to me that it doesn't matter which one you assign to the
y-axis.

Brian
eaton@ncar.ucar.edu