Add instrument and BODC code as special keyword in DwCA export

[Jean-Olivier Irisson]

From Erico B, Blue Cloud:

I've checked the ExoTaxa records from EurOBIS, e.g. http://ipt.vliz.be/eurobis/eml.do?r=dasid_6505&v=1.1

Here the instrument is present, altough in the keyword section along other keywords:

<keywordSet>
    <keyword>EcoTaxa</keyword>
    <keyword>Imaging</keyword>
    <keyword>ZooSCAN</keyword>
    <keywordThesaurus>ASFA</keywordThesaurus>
</keywordSet>

It seems that EML have place for a dedicated instrument metadata element, like this:

<methods>
    <methodStep>
        <description>Acquisition</description>
        <instrumentation>ZooSCAN</instrumentation>
    </methodStep>
</methods>

However this functionality it seems it is not available in the EML GBIF profile XML schema used by EurOBIS (maybe the imported EML schema is not updated), so making this addition will invalidate the original XML document.

I'd suggest to use a separate keyword set for the instrument, pointing to the devices vocab:

<keywordSet>
    <keyword>Hydroptic ZooSCAN imaging sensor</keyword>
    <keywordThesaurus>SeaVoX Device Catalogue</keywordThesaurus>
</keywordSet>

For improved semantics the following could be added as well (or used in place of the previous block):

<keywordSet>
    <keyword>http://vocab.nerc.ac.uk/collection/L22/current/TOOL1581/</keyword>
    <keywordThesaurus>http://vocab.nerc.ac.uk/collection/L22/current/</keywordThesaurus>
</keywordSet>

The most important would be to add the code, rather than the name of the instrument. It is machine readable and constitutes a more stable reference. Only put the name when the code does not exist; in that case the Thesaurus will be empty.