capture attributes info on iso19139

[pvgenuchten]

in #159 we've added the option to capture attribute info on mcf, a next step would be to capture this information also in the iso19139 documents generated from pygeometa. I'm starting this thread here to hear some views on this.

current practices

• at iso19115-3 it is possible to embed featurecatalogue information
• at iso19139:2007 this was not yet fully possible, the featuretypes element (which seems intended for this) is encoded as gco:GenericName_PropertyType, which many software can't handle well. Instead, people are generally referencing a dedicated iso19110:2005 record as featurecatalogue-citation holding the attributes information

implementation options for iso19139:2007

• No action > endorse the iso19115-3
• have a separate output scheme to export the same mcf as iso19110:2005 and provide a mechanism to establish linkage between the 2 exported records
• develop and endorse an extension to iso19139:2007 which fixes the aspect of embedding a featurecatalogue by overriding the gco:GenericName_PropertyType of gmd:featureTypes with a proper iso19110:2005 featuretypes type

schema information in other metadata conventions

• The data package convention contains a schema property which points to the relevant schema file
• The Stat DCAT AP profile adopted conventions to embed attribute and dimension information, adopted from SDMX