[postgis-users] Projection for Calculating Area

[J. Andrew Rogers]

On Feb 21, 2008, at 9:56 AM, Dylan Beaudette wrote:
> This touches on one of the fundamental issues with geographic data:  
> when you
> want to compute cartesian statistics (length, area, etc. in a planar  
> sense)
> you are going to have to make a compromise in
>
> shape
> direction
> area
>
> AND the larger the region you want to work with the more drastic the
> distortion on 2/3 of the above parameters you will encounter.


Isn't this largely a fundamental issue because, for good historical  
reasons, we do geometry computations on 2-dimensional projections of a  
complex object in 3-space?  Your point is absolutely correct, but I  
have always been interested in the reasons why geospatial is still  
computed almost purely from projections in the computer age.  (Not to  
hijack the thread, but I have always been genuinely curious about  
this; most of the underlying rationale seems suspect for an increasing  
number of computer-based applications.)

Cheers,

J. Andrew Rogers