Ckan单一空间元数据文档收集器

Question

I'm trying to harvest from a single spatial metadata document(using doc.py harvester from the ckanext-spatial) into my Ckan site but the format and the structure of the document is not specified. I used a xml format(as I noticed from the guess_standart() method in the base.py file) but I don't know what structure to implement in order to harvest successfully from it. Any ideas?

Answer 1

ckanext-spatial supports primarily ISO-19139 standard (which is based on the more abstract ISO-19115 model), but also US's FGDC standard which is a variant of the ISO one.

To get a copy of the ISO standard itself you need to pay for a copy. However there are plenty of open examples and documentation around, freely available. eg http://inspire.ec.europa.eu/documents/Metadata/MD_IR_and_ISO_20131029.pdf

ckanext-spatial will convert the main ISO-19139 fields to CKAN fields. So if all you want is spatial metadata in CKAN then you could achieve this more easily by just typing this into the CKAN form, and use the 'extra' fields to store things that aren't on the form by default, such as the spatial extent. Harvesting is useful in two circumstances:

1. You have metadata elsewhere. Harvesting is a convenient way to import it and keep it in sync over time.

2. You want to be able to serve up the original spatial metadata records. (The metadata that is converted to CKAN's internal format tends to be lossy because the ISO standard is labyrinthine.) This tends to be what GIS experts want, and is a requirement of the European INSPIRE programme.