[GRASS5] [bug #3526] (grass) Sphere: Problem using r.in.gdal to import geoTIFF of US NDVI

It is my opinion that the WKT projection description in the metadata is
wrong. In WKT the ellipsoid is described by two parameters: the semi-major
axis and the inverse flattening. For a sphere the flattening is 0 and so the
inverse flattening is infinity. If the metadata is modified to read
SPHEROID["Sphere",6370997,"inf",AUTHORITY["EPSG","7035"]]
instead of
SPHEROID["Sphere",6370997,0,AUTHORITY["EPSG","7035"]]
then GRASS creates a valid PROJ_INFO file.

The problem can be worked around by editing the line b: -inf in the
PROJ_INFO to read either "b: 6370997" or "es: 0".

Perhaps we could change GRASS to accept 0 as well as "inf" as representing a
sphere to allow for other broken software if this is common. Suggestions /
opinions on the most appropriate course of action are welcome.

This is all very complicated and hard to get my ahead around so please
challenge/question this if it looks like I've made a mistake.

Paul

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