On 3. juli. 2008, at 23.02, Dane Springmeyer wrote:
...
However - I have another dataset from the middle east, and
approaching this data the same way, even trying to reverse the
dataset from the images, it still fails:
http://www.ia-stud.hiof.no/~kjellare/misc/gdal_fail1.png
http://www.ia-stud.hiof.no/~kjellare/misc/gdal_fail2.png
I can see from the Qgis mouse coordinates in the lower right that
the shapefile you created likely has x,y coordinates in a projected
coordinate system (at least different from WGS 84/4326). My first
(wild) guess would be to add a .prj file from spatialreference.org
for a UTM zone that covers your area of the middle east (you'll be
need to find out what exact zone number is needed if it is in UTM).
I would try:
http://www.google.com/search?hl=en&q=site%3Ahttp%3A%2F%2Fspatialreference.org+utm+middle+east&btnG=Search
Not having worked much with GIS systems or projection/coordinate
systems before, I am struggling to understand the meaning of all this.
However, the following (esriwkt) was the result of the visit to the
link above, and I am injected it into the .prj file before running the
script all over again:
PROJCS["Nahrwan 1967 / UTM zone 39N",GEOGCS["Nahrwan
1967",DATUM["D_Nahrwan_1967",SPHEROID["Clarke_1880_RGS",
6378249.145,293.465]],PRIMEM["Greenwich",0],UNIT["Degree",
0.017453292519943295
]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",
0],PARAMETER["central_meridian",51],PARAMETER["scale_factor",
0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",
0],UNIT["Meter",1]]
Please let me know if I got this completely wrong and please excuse my
lack of knowledge here.
UTM is a likely candidate if the data came from a GPS unit, but its
just a guess.
It did. Garmin GPSMap 60 CS.
But, still, even with the new projection file, this thing still looks
like this:
http://www.ia-stud.hiof.no/~kjellare/misc/gdal_fail3_lebanon.png
I even tried reversing the coordinates in the input file, but with
almost the same result:
http://www.ia-stud.hiof.no/~kjellare/misc/gdal_fail3_lebanon2.png
Hm... Not sure how to proceed from here.
...
In Qgis you should be able to reproject to UTM and label your
points. Qgis will also export to PNG format if that is what you
want. However I don't think that Qgis will output an ESRI world file
(the only way that I know to keep a PNG spatially reference... but
the application uDIG will output a .wld world file to spatially
reference a PNG).
I am in need of a open source command-line style software here, in
order to automate this entire endevour.
Both uDIG and QGIS appears to be GUI style applications.
Are there a way around this to let me export the shapefiles I have to
a .png raster file to complete my mission?
Kjell Are
_______________________________________________
Discuss mailing list
Discuss@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/discuss
