[GRASS-user] decoding esri file format

[Stuart Edwards]

Thanks Daniel and Helmut

On Jan 28, 2013, at 2:50 PM, Daniel Victoria wrote:

> What do you mean by connect the metadata to the Tif? Ypu mean get it in the right projection? Or export the metadata from Arc to some sort of metadata catalog (geonetwork)?
I was hoping that there was some magic that would allow GRASS and/or GDAL to actually read the whole directory and figure out which files it needed to display the image in its correct projection and location.  After quite a lot of time I have decided that this is not possible - although I do know a lot more about GDAL than when I started, which is not a bad thing.

> 
> If you just want to get the correct coordinate system, then your best bet is to do as Helmut said. Import it with r.in.gdal or use gdal_translate.
Yes, this works fine and the gtiff metadata is updated to reflect the correct projection.  However when displayed, the 18" x 36" drawing is upside down, 1.5 ft x 3 ft in size and located in the bottom left corner of the region at 0,0.  This is because the georeferencing of the corners (ullr) is missing.  I tried to guess where the corners were and use gdal_translate to move it into position - I got it close, but no cigar.

> 
> Here is a breakdown of what each of those file normally contains in the ArcGIS world:
> xx_v2.txt: This is not a standard arc file when dealing with tiff files. It's probably something the data provider created
this looks like a list of 20 georeferenced points - except that the equivalent pixel values aren't given anywhere that I can see
> xx.aux - Auxiliary file which contains information about raster statistics, histogram, etc
> xx.rrd - that is the pyramid layer. Used for fast rendering. Don't think grass will use that
> xx.tfwx - I believe this is the tif georeferencing file but normally you don't have the last x
called a 'world' file - as in "what in the world can I do with this?"
> xx.tif - you actual data
> xx.tif.aux.xml - Metadata created using ESRIs tool (ArcCatalog). I've often seen it using the FGDC metadata standard.
> 
> 
> Now, looking at the xml file I see:
> -<SpatialReference xsi:type="typens:ProjectedCoordinateSystem"> <WKT>PROJCS["NAD_1983_StatePlane_Ohio_South_FIPS_3402_Feet",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",1968500.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-82.5],PARAMETER["Standard_Parallel_1",38.73333333333333],PARAMETER["Standard_Parallel_2",40.03333333333333],PARAMETER["Latitude_Of_Origin",38.0],UNIT["Foot_US",0.3048006096012192],AUTHORITY["EPSG",3735]]</WKT>
> 
> So it looks as thou your data is in epsg:3735. r.in.gdal with the override flag in a State Plane location should work
I could probably have printed the tif and georeferenced it myself ..... live and learn.  I sent a note to the supplier pleading for non-proprietary formatting of public data files ......

thanks again,

Stu