[GRASS-user] Reprojection from LLC to UTM (various zones)

[Michael Barton]

Actually, NVIZ DOES handle such maps OK. You have to mess with the
z-exaggeration setting a bit, but you can display latlon maps in 2.5D. A
real plus for GRASS over other GIS and visualization systems.

Michael


On 8/23/07 9:32 AM, "Miriam España" <mespana at ugr.es> wrote:

> 
> Hello again,
> 
> ok, I understand that it's not the appropriate projection for the zone, but
> it's part of my problem: my objective it's to visualize a raster3d in nviz,
> but the r3 map it's in Lambert Conic conformal, and it  seems like Nviz
> can't represent maps in locations differents from XY or UTM (respect UTM,
> I'm not sure, anybody can confirm this?).
> 
> It's for this reason... any suggestion?
> 
> Thanks for all,
> 
> Miriam 
> 
> 
> Michael Barton wrote:
>> 
>> A UTM projection is not really appropriate for all of North America, which
>> crosses multiple UTM zones. It is only accurate within a single zone. Try
>> a
>> different projection that is appropriate for such large areas (e.g.,
>> Lambert
>> Conformal Conic).
>> 
>> Michael
>> 
>> 
>> On 8/23/07 2:01 AM, "Miriam E. A." <mespana at ugr.es> wrote:
>> 
>>> 
>>> Hello everybody,
>>> 
>>> I'm triying to reproject a map of north america form llc to utm, but
>>> Grass
>>> reports an error about input map is outside output region.
>>> 
>>> I choose zone 16N as center of the map, defining a region as the next, in
>>> the UTM Location:
>>> 
>>> GRASS 6.3.cvs (UTM):~ > g.proj -p
>>> -PROJ_INFO-------------------------------------------------
>>> name       : UTM
>>> datum      : nad27
>>> towgs84    : -22.000,157.000,176.000
>>> proj       : utm
>>> ellps      : clark66
>>> a          : 6378206.4000000004
>>> es         : 0.0067686580
>>> f          : 294.9786982000
>>> zone       : 16
>>> -PROJ_UNITS------------------------------------------------
>>> unit       : meter
>>> units      : meters
>>> meters     : 1.0
>>> 
>>> g.region n=10000000 s=0 e=10000000 w=0
>>> 
>>> to cover the greatest area possible.
>>> 
>>> Does grass support regions crossing various zones UTM? And, UTM considers
>>> north as 0 to avoid negative coords in the north hemisphere, but in GRASS
>>> south must be 0...
>>> 
>>> Maybe i'm very wrong.
>>> 
>>> Thanks for your attention and for the help (in this and previous emails
>>> and irc).
>>> 
>>> Miriam
>> 
>> __________________________________________
>> Michael Barton, Professor of Anthropology
>> Director of Graduate Studies
>> School of Human Evolution & Social Change
>> Center for Social Dynamics & Complexity
>> Arizona State University
>> 
>> phone: 480-965-6213
>> fax: 480-965-7671
>> www: http://www.public.asu.edu/~cmbarton
>> 
>> 
>> _______________________________________________
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>> 

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton