Re: [gdal-dev] orginfo and prj files

Lucena, Ivan ivan.lucena at
Thu Aug 14 17:14:06 EDT 2008


>  The shapefile driver does run morphFromESRI() and we can confirm
>  that takes place because the D_ has been stripped from the datum
>  name.  However, morphFromESRI() will *not* add in authority nodes
>  or otherwise fill in missing information.  It just changes a few known
>  patterns from ESRI names to OGR names (projection names, parameters
>  datums).

I got it.

>  Your earlier question related to whether it was possible to establish
>  what EPSG coordinate system an ESRI .prj file is.  There is no practical
>  way to do this with OGRSpatialReference.

So, one would need to write a C/C++ code to go through the csv tables (using the CPL_CSV.h type and functions) trying to match the names/values in order to recover the codes, keeping track of the relationships between Datum, Reference system and Projection system. Not a easy task and also process time consuming, I believe.

But one end-user practical solution would be to use org2org to export to another format which the driver does explicitly shows the EPSG code. Would that be possible? Does other OGR driver shows authority code?



More information about the gdal-dev mailing list