TAG SPATIAL REFERENCE SYSTEM (GeM+)

This section contains information about the reference system of the dataset. According to the CEN, this section is optional, that is, although the data may be available it is not obligatory to document them. Nevertheless, GeM+ considers this section as obligatory.

The content of this section is based on the proposals of the ENV 12762 and ENV 12657 European standards and the CSDGM American standard. Currently only those aspects corresponding to the horizontal reference system have been implemented.

This section is not stored in the REL file (format 4) for structured vector nodes and polygons since the reference system is that of the related arcs. This assures that the arc layers and the related nodes and polygons are coherently documented (in the older documentation files it was possible to create contradictions between the documented reference systems used by a single set of arcs and related nodes and polygons).

In the case of metadata on a polygon or node set read from older documentation files, the reference system shown in GeM+ will be that documented in the DVP or the DVN independently of the reference system documented in the arc set (and independently of the format of the metadata of the arc file).

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