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

[Corrado]

On Thursday 23 October 2008 11:38:47 Daniel Victoria wrote:
Thanks Nikos and Daniel again!

I was seriously hoping that GRASS would have managed the conversion for 
me .... I do not think we could actually define the resolution by hand (it 
would not really be accepted in a paper)!

> 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