[GRASSLIST:4932] Re: rasters reprojection UTM -> LAEA

[Markus Neteler]

Rado,

On Mon, Nov 22, 2004 at 01:08:19PM +0100, Rado Bonk wrote:
> Dear GRASS users,
> 
> I have problems with reprojecting ArcINFO rasters from UTM to LAEA. I 
> defined LOCATION to imported the rasters (based on data provider info):
> 
> name: UTM
> proj: utm
> ellps: grs80
> a: 6378137.0000000000
> es: 0.0066943800
> f: 298.2572221010
> zone: 33

On Wed, Nov 24, 2004 at 09:14:48AM +0100, Rado Bonk wrote:
> Markus,
> 
> The file is laser scanned DEM of [...] 
> I also have XYZ ASCII file from 
> which they interpolated 5m grid.
> 
> Thanks,
> 
> Rado
> 
> 
> OUTPUTS:
> 

> GRASS:~> gdalinfo 3753no
> 
> Driver: AIG/Arc/Info Binary Grid
> Size is 1138, 559
> Coordinate System is `'
> Origin = (3471422.500000,5791542.500000)
> Pixel Size = (5.00000000,-5.00000000)
> Corner Coordinates:
> Upper Left  ( 3471422.500, 5791542.500) 
> Lower Left  ( 3471422.500, 5788747.500) 
> Upper Right ( 3477112.500, 5791542.500) 
> Lower Right ( 3477112.500, 5788747.500) 
> Center      ( 3474267.500, 5790145.000) 
> Band 1 Block=285x4 Type=Float32, ColorInterp=Undefined
> Min=0.000 Max=37.980 
> NoData Value=-3.40282e+38


As you see the data set does not contain Coordinate System info etc.
So GRASS cannot define a location.
 
One way to solve the problem is to use 'gdal_translate' to
assign the missing Coordinate System information:


#check EPSG file for IDs: /usr/local/share/proj/epsg
## ETRS89 / UTM zone 33N
## <25833> +proj=utm +zone=33 +ellps=GRS80 +units=m +no_defs  <>

#you may want to add a datum definition to below command
#using the +towgs= parameter:

gdal_translate -of GTIFF -a_srs '+init=epsg:25833' \
             3753no.tif 3753no_utm33N.tif 

gdalinfo 3753no_utm33N.tif

Then you can import it with r.in.gdal (not using '-o' flag!)
and create a new location from the 3753no_utm33N.tif file.

Hope this helps

 Markus

-- 
Markus Neteler     <neteler itc it>       http://mpa.itc.it
ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
MPBA - Predictive Models for Biol. & Environ. Data Analysis
Via Sommarive, 18        -       38050 Povo (Trento), Italy