[OSGeo-Discuss] Call for help: GDAL and txt2shp.py

[Kjell Are Refsvik]

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

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