|Arc/Info Coverage (Binary)
Arc/Info 7.x binary coverages are supported by the GDB library for import with a number of limitations. A coverage is selected based on the name of the coverage directory, rather than any of the files in the directory.
Point Coverages: The points (lab.adf) are imported as a single vector layer. If a pat.adf file exists with point attributes (COVER.PAT in info) then this will also be imported and attached to the points. If no point attribute table exists the points will only have one attribute, called USER-ID, containing what would be the COVER-ID field in a point attribute table.
Arc Coverage: The arcs (arc.adf) are imported as a single vector layer. If an arc attribute file exists (aat.adf or COVER.AAT in info) then it will also be imported, as well as the attributes associated with each of the arcs. Whether or not the aat.adf file exists each arc will have attributes FNODE (from node), TNODE (to node), LPOLY (left polygon), RPOLY (right polygon) which are related to topology, and not particularly useful at this time. If no aat.adf file exists the user attribute will also be attached to the arcs with the name USER-ID.
Polygon Coverage: A polygon coverage is treated as two layers: an arc coverage containing the polygon boundary arcs, and a point coverage containing the polygon centroids and any associated polygon attributes.
If the coverage has a defined projection (prj.adf) then this will also be read and associated with the vector layers. At this time only a few simple projections will be properly recognized including UTM, Geographic, and State Plane.
There is currently no support for update, or creation of new coverages.
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