Open adamml opened 4 years ago
@adamml @jyucsiro
Rob has raised a query on the PR looking to update the vocabulary with respect to https://github.com/opengeospatial/NamingAuthority/pull/39
Should
@prefix dcat: <http://www.w3.org/ns/dcat#>.
bald:Container a dcat:Dataset.
be
@prefix dcat: <http://www.w3.org/ns/dcat#>.
bald:Container rdfs:subClassOf dcat:Dataset.
?
Please may you consider this question?
thank you mark
fwiw, i think that the use of rdfs:subClassOf
is valid here
@marqh I've been trying to find headspace to think about this between meetings. I'd agree with you that it's valid here, yes.
many thanks @adamml
I have updated the request for change with the OGC NA
The update to the BALD vocabulary has now been adopted
https://github.com/opengeospatial/NamingAuthority/pull/39
A bald:Container instance is now also a dcat:Dataset
is there a more definitive definition of a netCDF file than
dct:format [
a dct:MediaType;
dct:identifier <http://vocab.nerc.ac.uk/collection/M01/current/NC/>
]
We should consider adding this infpormation to the Schema.org representation of BALD as well, e.g.;
{
"@context": "https://schema.org/",
"@type": "Dataset",
"distribution": {
"@type": "DataDownload",
"contentUrl": "http://",
"encodingFormat": [
"application/x-netcdf",
"http://vocab.nerc.ac.uk/collection/M01/current/NC/"
]
}
}
Sorry if this discussion is already closed, I can raise a new issue instead if appropriate. The containment part of section 6 states that groups can be "contained by" files, which I interpret as:
<file.nc> a bald:Container ;
bald:contains <file.nc/> .
Or, "the root group is contained by the file". Is this interpretation valid / should the wording of that section be changed to reflect the intentions discussed above?
Rationale
In discussions on the group telecon, it came to light that the Binary Array LD (BALD) specification would describe the contents of the NetCDF file for NetCDF-LD, but not provide a link to the NetCDF file itself. It became apparent that an extra predicate would be needed in the RDF representation of a Binary Array file in order to support this.
The file location should be an optional, user-specified parameter supplied at runtime.
Approach
A number of options have been considered:
Due to the stability and maturity of the vocabularies, it was decided to focus on the Schema.org or DCAT options.
A further consideration was the grouping of NetCDF files into collections, which may be acheived in either Schema.org or DCAT if the contents of the NetCDF file are considered to be a
Dataset
and the collection of the NetCDF files aDataCatalog
. The ability to nest, or to create heirarchies of catalogues was also considered, such as a collection of NetCDF files being available with other files or collections through a THREDDS server. While we do not provide an implementation pathway for this, the consideration motivated us to focus on DCAT which at the time of writing supports nesting catalogues, whereas Schema.org does not.Boilerplate code
First an addition to the BALD ontology will be required:
Then the following boilerplate would allow a software agent to traverse the graph to find the file to download the NetCDF data from:
Further Considerations
Questions
@jyucsiro, @marqh a couple of questions/topics for discussion: