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

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