[Proj] Need help converting Goode to latlon

David Turover dturover at student.santarosa.edu
Thu Jul 23 00:14:46 EST 2009

On Wed, Jul 22, 2009 at 10:04:18AM -0400, Gerald I. Evenden wrote:
> On Wednesday 22 July 2009 2:39:52 am David Turover wrote:
> >
> > Example: http://segfault.cs.sonoma.edu/~dturover/gisbug/projectionError.jpg
> The projection in the above jpeg looks like Near-sided perspective.  At any 
> rate, it certainly is not Goode's pseudocylindrical Homolosine.

The jpeg is the result of attempting to reproject from Goode to geographic
coordinates. I have confirmed with an ESRI tool that the original shape is
in Goode, so the problem is in my use of proj.

Additional notes:

+proj=sinu produces similar results except that the tip of South America
is pulled further west. Since sinu is the middle half of goode and the
polar regions use a different algorithm, this should be expected.
However, it may be worth mentioning that I can't get sinu to match the
country shapes to their borders either.

Most tweaks that I attempted to make to the proj arguments resulted in
no change in the output, including turning off +no_defs and giving both
the input and output projections the same datum "+datum=WGS84".

I had the output projection as a null string to default to geographical
coordinates. "+proj=latlon +units=degrees" gives the same result.

Overstating +a (the earth's radius?) will pull shapes to the east as
they are stretched, including things at the equator that were well
placed before.

"+lon_0=-90" drew the South America shapes in the middle of the Pacific
Ocean. This makes sense since the original projection is based on the
Greenwich meridian, so this just moved everything west.

I turned on the PROJ_DEBUG environment variable but the only notice it
gave was that proj_def.dat could not be opened. I fixed this by exporting
PROJ_LIB so it searched in the right place. This did not affect the

The ESRI projection definition includes an option named "Option" that
is set to 1. This does not sound very important, but might it have an

 - David T. 

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