[GRASSLIST:2178] Re: Projection questions
rshepard at appl-ecosys.com
Fri Jul 27 13:22:21 EDT 2001
On Fri, 27 Jul 2001, Frank Warmerdam wrote:
> > unit: unknown
> > units: unknowns
> > meter: 1
> The "unit" value is the singular name for the linear unit. The "units" value is
> the plural. The "meter:" value is the size of this unit in meters. Since this
> value is 1.0 we see that it is really in unit meters but r.in.gdal isn't
> establishing this correctly.
Thanks very much. Just to confirm my understanding. If the map is
projected in State Plane Coordinates/NAD27, then the file would read:
When you write that r.in.gdal "isn't establishing this correctly", do you
mean that it's just not writing the PROJ_UNITS file correctly?
> > proj: 1
> The association of 1 with UTM is "in the code", and not controlled by any
> configuration files. GRASS programs that report on projections should
> know how to translate into human readable form.
Hmm-m-m-m. I think we're getting to another question here. That's good, by
the way. :-)
I'm reorganizing my entire data structure to make GRASS5 happy (I'm told
the existing structure should work, but my problems with r.in.gdal+r.proj
prove otherwise). As most of my current projects are in the Pacific
Northwest of the U.S., I'm setting up a top-level location called PERMANENT
that defines the boundaries of this left third of the country. The
projection is Albers Equal Area (aea on the /usr/local/grass5/etc/prjections
file list). How do I specify that in a numeric equivalent?
I know that '99' is used for both 'user specified' and 'spc', but I cannot
find a list of codes for other projections.
And, can we assume that all GRASS modules that work with/report on
projections know what the projection is? If this is the case, do we need to
specify it in the PROJ_INFO file?
Stumbling toward understanding,
Dr. Richard B. Shepard, President
Applied Ecosystem Services, Inc. (TM)
2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
+ 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard at appl-ecosys.com
Making environmentally-responsible mining happen.
More information about the grass-user