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

Paul Kelly via RT grass-bugs at intevation.de
Tue Aug 23 14:53:54 EDT 2005


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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