[Qgis-developer] Spatial reference systems and Area of applicability

[Even Rouault]

Hi,

This is something I discussed with Paolo during the past Code Sprint. In the 
original EPSG databases, there is an area of applicability defined as a 
bounding box in latitude,longitude for each spatial reference system. In the 
import process of the EPSG database used for libgeotiff, GDAL, proj.4 and 
PostGIS ( detailed in 
http://svn.osgeo.org/metacrs/geotiff/trunk/libgeotiff/csv/README ), that area of 
applicability is not currently imported in the .csv files concerning geographic 
or projected SRS (but they are imported for datum shift transforms).

A potential improvement would be to add it and expose it in the GDAL 
OGRSpatialReference object, so that QGIS could benefit from it.
This could be used for example :
- to warn the user when reprojection to a SRS is completely or partially out 
of its area of applicability
- to filter the SRS catalog to offer only the relevant SRS at a point or on a 
zone
- ...

Even

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