[GRASS5] problems with [rsv].proj

[Eric G. Miller]

On Thu, May 30, 2002 at 05:39:58AM +0100, Glynn Clements wrote:

> In the longer term, we should re-think the architecture of the PROJ
> library. There are many practical applications where it would be
> useful to have more information about the overall "nature" of a
> projection than just a pair of functions which project individual
> points.

While not supporting all the nifty cartographic projections like proj4,
the Geotrans projection routines from NIMA will signal an error if the
coordinate is outside the reasonable limits of the projection.  The code
for this library is pretty well thought out, but it is limited to about
15 of the most common projections (though that covers most needs) and
some things like the projection used in F-16 fighter jets could be done
without ;-).  To support grid shift type datum transformations would
require hacking into the datum code.  One nice thing, is it includes
geoid (EGM96) vertical corrections for wgs84 ellipsoid vs. mean sea
level.  Another thing some might find nice is the various projection
error values and significant digit rounding it provides (based on some
scale factor).

-- 
Eric G. Miller <egm2 at jps.net>