Failure on Re: [GRASS-user] Help: Converting a raster map between locations (from wgs84 lat / long to UTM)

[Corrado]

Dear Daniel, dear Nikos, dear list,

I have tried everything I could. I read the GRASS books chapters and the 
documentation. It does not work.

The problem is that the files I have are in WGS84 unprojected. See here:

http://www.worldclim.org/format.htm

Whichever procedure I use, whther Daniel's or the book (for example: page 47), 
the problem is always the same.

I create a location + mapset + map with the worldclim data (location01). I 
load the original data, and I call the raster map "precipitation". I generate 
the correct box with v.region and I call it "test". I create a new location + 
mapset (utm + osgb), called location02. I run v.proj in location B pointing 
at map "test" 

v.proj input=test location=location01 mapset=PERMANENT


I have the same problem: 

PROJ_INFO file not found for location location01

But of course the projection is not defined, the data are unprojected!

I am slowly getting desperate .... I have been working on it several days and 
cannot get a sensible result. I have tried with different datum 
transformation parameters for osgb36 and trying to project .... but the 
results are very unreliable ....

Do you know what should I do?

On Thursday 23 October 2008 11:38:47 Daniel Victoria wrote:
> Corrado,
>
> What v.in.region does is create a vector that surrounds your current
> region. Then, when you run v.proj, the vector covering the region is
> brought to your target location so you know where your projected
> raster should be at...
>
> The "manual labor" after that is setting the resolution correctly. You
> could then use some rule of thumb like 3arcsec ~= 90 m or, try to set
> the number of columns/rows in your target region similar to your
> lat/lon region. But this latter option does not work so well if your
> raster is to be tilted a lot...
>
> On an "additional" question: How do people set the resolution
> correctly when transforming from lat/lon to meter and vice-versa? Are
> there any other methods besides the ones I mentioned?
>
> Cheers
> Daniel
>
> On Thu, Oct 23, 2008 at 8:16 AM, Nikos Alexandris
>
> <nikos.alexandris at felis.uni-freiburg.de> wrote:
> > On Thu, 2008-10-23 at 10:40 +0100, Corrado wrote:
> >> Thanks Nikos, thanks Daniel!
> >>
> >> Unfortunately, my map is a raster map, not a vector .... can I still
> >> use
> >> v.in.region and v.proj?
> >>
> >> Thanks
> >
> > [...]
> >
> > Hi Corrado!
> >
> > For sure!! You can use v.in.region anytime since it deals with the
> > current region and not with a specific map.
> >
> > Regards, Nikos



-- 
Corrado Topi

Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk