P01 term for Area

[peterdesmet]

Area is defined as:

Area of sea surveyed during the observation bin in km². Can only remain empty if Distance is used.

There are two existing terms that come close:

Sample area (aircraft survey)

• http://vocab.nerc.ac.uk/collection/P01/current/SAMPARAC/
• The areal extent of the portion of the Earth's surface included in a given sampling event (such as an animal count) from an aircraft
• Related to square km

Area (representative)

• http://vocab.nerc.ac.uk/collection/P01/current/NEWCXX01/
• The area over which the measurements made are considered to be representative.
• Relate to square m

The first one looks great, but @nicolasvanermen, I assume ESAS data could use area for ship based observations as well? Or is the match close enough?

[peterdesmet]

Note that it is not https://vocab.nerc.ac.uk/collection/Q01/current/Q0100017/ "Sampling device aperture surface area"

[nicolasvanermen]

Note that the second relates to square m instead of km... These are two seperate vocabs, does this imply two columns, or can they be integrated in one field? And is it necessary to "contain" everything in a vocabulary? Even such generic fields as distance and area?

[peterdesmet]

These terms are not controlled vocabularies, but standardized description of measurement methods. It’s good to link to one of if we can, because it allows cross-dataset standardization.

In these issues I describe which one could apply. If we can’t find a good match, that is ok too: then we don’t link.

[peterdesmet]

@rubenpp7 @pieterprovoost see the issue description. We have a term "area" in ESAS, that describes "Area of sea surveyed during the observation bin in km²". This can be done from aircraft or boat. Would you say that maps sufficiently to "Sample area (aircraft survey)" at http://vocab.nerc.ac.uk/collection/P01/current/SAMPARAC/ for us to use that URL as a measurementTypeID

[pieterprovoost]

@peterdesmet But these are not (all) aerial surveys, right? In that case we will need another term.

@gwemon

[peterdesmet]

Indeed, these are not all aerial surveys. I have looked through other terms and can't find (another) good fit. Is it better to leave measurementTypeID empty then?

[gwemon]

Thanks for pinging me @pieterprovoost We could create a more generic term than SAMPARAC for "Area of sampling event"? This will be created using our semantic model so re-using Area as defined in S06 and adding a new term "sampling event" to the S29 vocabulary to give "Area of sampling event". Once we have this new term defined we we also be able to harmonise existing sampling event-related P01 terms reusing the same components. i.e. SAMPARAC which is a term that is still not expressed using our semantic model will become "Area of sampling event by aircraft survey". Would that work for you? Also bear in mind that the units we associate with a P01 concept in the NVS is a BODC unit only. Unfortunately we cannot change this because too much legacy is dependent on it. However you must define the unit in your dataset independently of the P01 term and you can use whichever unit you want providing it has the same dimension (i.e. L^2 in this case)

[peterdesmet]

I for one support a more generic Area of sampling event term. 👍 We can indeed define our unit (km²) separately.

[peterdesmet]

Once the term becomes available at NERC, measurementTypeID in the following code should be updated to reference it:

https://github.com/inbo/esas2obis/blob/ba1a98396963b668b38f35383f4eb03ad549ab51/sql/dwc_emof.sql#L246-L256

[peterdesmet]

measurementTypeID for "Area" updated to https://vocab.nerc.ac.uk/collection/P01/current/SAMPARAX/ in 60ee1ea