[GRASSLIST:3686] Re: Error in g.setproj for State Plane projection

[Eric G. Miller]

On Fri, May 17, 2002 at 04:34:28PM -0400, John Gillette wrote:
> 
> I have just independently verified that creating a state 
> plane location for IN doesn't work.  I tried IL (also a
> TM projection with 2 zones in the state) and in works 
> fine.  I use NC which works fine.  When setting up a 
> location the program reports that a location is created
> but not a projection.  When you run g.setproj you get 
> the error as previously reported.  [ref GRASSLIST
> 3680 and 3681]

Okay. Thanks for the info.

> I have additional questions:
> 
> g.region reports ellipsoid: ** unknown (default WGS84) **
> even though I set clark66.  Is this correct behavior? If 
> I set the datum shouldn't this automatically set the 
> ellipsoid?

You would think!  With State Plane, the ellipsoid parameter doesn't get
set (though, the defining spheroid parameters do). In GRASS 5.0, the
datum parameter is mostly informational (you really need ellipsoid
parameters though).

> When I specify feet, g.projinfo reports 
> unit:   foot
> units:  feet
> meters: 0.3048000000
> 
> Is there a way to specify a "Survey foot" (0.3048006096)?

Unfortunately, no.  You might hack PROJ_INFO for the correct conversion,
though I can't guarantee it'll always be used.  This error's been in
GRASS for some time...

The entire projection handling code of GRASS needs a redesign and
rewrite.  It was felt that this should be put off to 5.1 since a good
redesign will probably break things all over the place.

-- 
Eric G. Miller <egm2 at jps.net>