[Proj] Custom projection wildly inaccurate

Greg Troxel gdt at ir.bbn.com
Mon Nov 20 08:36:24 EST 2006


  > There seem to be several approximations. Most straight (read: 
  > what you can do per proj/cs2cs command line alone) projective 
  > approximations are bad.
  > There is really only one way to do it correctly: use the 
  > official polynomial solution.

  Yes, but that's not easily translatable for use in Proj-based
  applications like GDAL and MapServer (as far I know, at least).
  We will most likely have to convert the data manually, but in
  the meantime it would be nice to have a bad-and-fast projection
  for demonstration and testing purposes.

One thing that would work, but perhaps set a bad precedent, is to
define a new projection in the proj source, that knows the
polynomials.  This would be a particular transform, rather than a
generic projection with parameters.  Alternatively, there could be a
polynomial transform with vast numbers of parameters.


-- 
    Greg Troxel <gdt at ir.bbn.com>
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