Hi List, i don't think QGIS allow raster reprojection. Maybe that's is your problem.
best regards Luigi Castro Cardeles 2009/11/18 Agustin Lobo <[email protected]> > No, what I was doing was different: > I was setting the project to 18S (not 18N) with OTF reprojection, the > raster to 18N > and the vector layers got reprojected to 18S but the raster > was not displayed. > I was expecting the raster to be located in the S hemisphere because > the coordinates are negative. In TNTmips, as the coordinates are negative, > even if the raster CRS is set > to 18N, the raster is displayed in the S hemisphere. Not sure if this > is what qgis should do, though, as we are dealing with wrongly annotated > raster layers: in UTM, S is S, not negative N. > > On the other hand, I assumed that if you set the project to 18N, then the > vector layers would projected to the N hemisphere. > But have tried defining the project as 18N as you say, used Coordinate > capture to check lon,lat, and actually get correct lon,lat coordinates (in > the S > hemisphere). The vector layers are reprojected to > 18, no matter the S or N, the original latitude correctly defines the > hemisphere. > > So it works "your way", thanks! > > Agus > > > > > Micha Silver wrote: > >> Hi Agus: >> I am actually able to do just that. I also am using some Landsat GEOCover >> images from below the equator, projected, as you say in UTM 39_N_. >> I load the raster, set the project CRS to that (UTM Northern) projection, >> and enable OTF projection. Then I can overlay vector layers, which are WGS84 >> Lon-Lat., and they are correctly located. >> >> It's usually not very helpful to say "works for me" but... >> Anyway, HTH, >> Micha >> >> >> Agustin Lobo wrote: >> >>> The global set of Landsat images on GEOCOVER >>> https://zulu.ssc.nasa.gov/mrsid/mrsid.pl >>> is on UTM/WGS projection >>> but with the Southern hemisphere tiles as UTM zones in the N with >>> negative coordinates. For example, a tile that should be at 18S is >>> actually 18N with negative coordinates >>> ("Non-standard UTM definition: For the southern hemisphere, the GeoTiff >>> files >>> contain positive zone numbers with negative northing coordinates") >>> >>> https://zulu.ssc.nasa.gov/mrsid/docs/GeoCover_circa_2000_Product_Description.pdf >>> >>> As we have some vector layers on geographic coordinates WGS84 and a >>> Geocover tile for 18S, >>> I've set the project as 18S, enabled CRS reprojection on the fly, and set >>> the raster CRS to 18N. Unfortunately, QGIS does not display the raster, >>> even >>> selecting zoom to layer extent. (Using Mimas). >>> >>> This is probably not a problem of QGIS, the Geocover projection is just >>> wrong, >>> but would like to know if there could be a way to circumvent this problem >>> to >>> be able to use GEOCOVER tiles of the S hemisphere within QGIS. >>> A way could be making a world file with the Georeferencer plugin, but >>> perhaps >>> there is a more general way. >>> >>> Thanks >>> >>> Agus >>> _______________________________________________ >>> Qgis-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/qgis-user >>> >>> This mail was received via Mail-SeCure System. >>> >>> >>> >> _______________________________________________ >> Qgis-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-user >> >> > > _______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user >
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