[GRASS-user] Re: [Proj] trouble transforming corine landcover raster projection Lambert laea to lcc

[Yves Jacolin]

Hi Markus,

May be it depends from where you downloaded the data. For my corine Land Cover 
file, I downloaded from here :
http://www.ifen.fr/donIndic/Donnees/corine/presentation.htm

Where it indicates that clc2000_fr got a Lambert conforme, zone II étendu 
projection :
http://www.ifen.fr/donIndic/Donnees/corine/methode.htm (bottom of the page, in 
the table).

All links are un french, sorry.

IFEN is the French Institute for ENvironments which publish the corine Land 
Cover data for france. I think they changed the projection to adapt it to the 
IGN data (ie BD topo, always info from the website).

My clc2000_fr data give me this infirmations :

Layer name: clc00_fr
Geometry: Polygon
Feature Count: 270465
Extent: (37256.000205, 1607395.375873) - (1207902.000605, 2687734.936295)
Layer SRS WKT:
PROJCS["NTF_Lambert_II_étendu",
    GEOGCS["GCS_NTF",
        DATUM["Nouvelle_Triangulation_Francaise",
            SPHEROID["Clarke_1880_IGN",6378249.2,293.46602]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Lambert_Conformal_Conic_1SP"],
    PARAMETER["False_Easting",600000.0],
    PARAMETER["False_Northing",2200000.0],
    PARAMETER["Central_Meridian",2.3372291667],
    PARAMETER["Standard_Parallel_1",45.8989188889],
    PARAMETER["Standard_Parallel_2",47.6960144444],
    PARAMETER["Scale_Factor",1.0],
    PARAMETER["Latitude_Of_Origin",46.8],
    UNIT["Meter",1.0]]
CODE_00: String (3.0)

Actually the question is from where Patrick downloaded his data?

Regards,

Y.
Le Dimanche 8 Avril 2007 21:16, Markus Neteler a écrit :
> On Sun, Apr 08, 2007 at 02:50:59PM +0200, Yves Jacolin wrote:
> > Hi Patrick,
> >
> > I succeed to import Corine Land Cover inside GRASS wittout problem.
> >
> > First of all, you need to create correct projection for your location.
> > Both of them seems to me incorrecte. Here what I get for my location
> > where I import corine Land Cover :
> > -PROJ_INFO-------------------------------------------------
> > name       : Lambert Conformal Conic
> > proj       : lcc
>
> I don't think that this is correct.
>
> Corine data are to my knowledge in ETRS89-LAEA, not LCC:
>
> GRASS 6.3.cvs (eu_laea):~ > g.proj -w
> PROJCS["Lambert Azimuthal Equal Area",
>     GEOGCS["grs80",
>         DATUM["European_Terrestrial_Reference_System_1989",
>            
> SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101],
> TOWGS84[0.000,0.000,0.000]],
>         PRIMEM["Greenwich",0],
>         UNIT["degree",0.0174532925199433]],
>     PROJECTION["Lambert_Azimuthal_Equal_Area"],
>     PARAMETER["latitude_of_center",52],
>     PARAMETER["longitude_of_center",10],
>     PARAMETER["false_easting",4321000],
>     PARAMETER["false_northing",3210000],
>     UNIT["meter",1]]
>
> This corresponds to ETRS89 / ETRS-LAEA: EPSG 3035.
>
> [...]
>
> > > GRASS 6.0.2 (corineurope):~ > g.region -p
> > > projection: 99 (Lambert Azimuthal Equal Area)
> > > zone:       0
> > > datum:      ** unknown (default: WGS84) **
>
> This datum recognition error I have fixed last year:
>
> 2006-11-07 13:51  markus
>         * convert.c: Handle non-standard ETRS_1989 datum name
>
> I think that it is relevant. Please update to GRASS 6.2.1
> to get the fix.
>
> Hope this helps,
> Markus
>
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-- 
Yves Jacolin
-------------
http://yjacolin.gloobe.org
http://softlibre.gloobe.org