[GRASSLIST:9231] krass/krassovsky

[Maciek Sieczka]

Dear developers,

Sevaral questions and complaints:

1. Does Grass need to have it's own names for ellipsoids? PROJ.4 for
Krassovsky uses "krass". Grass doesn't recognize it and requires
"krassovsky".

2. When creating a location from EPSG code in Grass, instead of
ellipsoids names "a" and "es" are used. Using ellipsoids names would
make PROJ_INFO less obscure.

3. Why does Grass recognize both GRS80 and grs80 (as well as gRs80 and
other mutations)? PROJ.4 demands GRS80 strictly.

4. Creating a PROJ_INFO form ESPG:2180 inserts a "datum: etrs89" line.
For what purpose? Wouldn't it better and conformal with PROJ.4 to use
towgs84: 0,0,0 simply? PROJ.4 doesn't even know what "etrs89" is.

5. Beginners I talk about PROJ.4 to find it hard to understand why
Grass, being dependant on PROJ.4 for handling coordinate systems,
doesn't fully follow it's convention and complicates issues complicated
enough. I agree with them - once I learn the correct syntax for a
projection definition to use with  cs2cs or gdalwarp I have to learn it
once more for Grass.

6. What's worse, PROJ_INFO actually follows PROJ.4 convention in some
aspects, but in other it doesn't. This is confussing - eg. once I learn
"tmerc" means the same for PROJ.4 and Grass I start suspecting that eg.
ellipsoids will be handled the same way. And it seems to be true for
some time, until this assumption fails for Krassovsky.

All these make teaching PROJ.4 and Grass more complicated than needed.
Anybody thinks the same? Opposite?

Maciek


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