InterOpMay2021Semantics < IVOA

---+ Semantics Session at the May 2021 Virtual Interop

Wed May 26, 2021, 5:00 UTC

See InterOpMay2021 for connection infos.

---++ Schedule

| *Speaker* | *Title*  | *Material* | *Time* |
| Markus  | A Review of the product-type Vocabulary | [[%ATTACHURL%/product-type.pdf][notes]] | 0:30 |
| Anaïs  | Progress on a vocabulary of object types  | [[%ATTACHURL%/2021-IVOA-Semantics-OBERTO.pdf][slides]] | 0:15 |
| Markus  | Vocabularies 2.0 in action  | [[%ATTACHURL%/voc-action.pdf][notes]] | 0:15 |


---++ Minutes

---+++ Product type Vocabulary

See slides. Items discussed:

Dynamical spectra came up at the Radio meeting on Tuesday

Visibilities are hard to categorize; do not really belong to 2d array, also 
because very specialised clients are required.

Scalar-map doesn't give dynamic spectra a home, it just excludes them; we still need a new terms for them, but of course it'd be great if we knew who would look for them when.

Or course, an array is map from scalars 0..n-1 to a single scalar...

The Planetary Data System has developed a similar vocabulary in the context of
their Informational Model to describe data structures.  They will post on the semantics list about it.

The sentiment that measurement is not convenient and too large is shared.

Some people cautioned that since this vocabulary should be adopted by obscore,
we need to have existing usage there in mind.

The current definition of spectra excludes multi-band spectra or spectra
mapping to both flux and polarisation.  This is probably not a good
idea, in particular because existing spectral clients can deal with this
kind of data.

It's not just IRAF that does spectra as 1d arrays, starlink/NDF does that too.
(not that there are many of those in the VO, but it's not such a weird way to
do it)

Periodograms would be scalar-maps in the current proposal, requiring an extra term (with good reason, as there are extra tools for them).

Concrete example:  What would the product type be for these sorts of products? https://archive.eso.org/cms/eso-data/help/1dspectra.html -- since they're consumed by usual spectral clients, we should work hard on keeping them within spectrum.


---+++ Status of Object types applied in SIMBAD - Anais

See slides; followup: Sem WG will work with CDS to bring 
the current state of affairs into the IVOA vocabulary repository.


---+++ Vocabularies in Action

See slides.

The extra accept header in the Javascript XMLHTTPRequest is for W3C semantics-style content negotiation: By default, you get back HTML from our repo, to get the convenient json you need to say you accept it (same for RDF/XML or Turtle).


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Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
pdf	2021-IVOA-Semantics-OBERTO.pdf	r1	manage	551.8 K	2021-05-26 - 06:20	MarkusDemleitner	Object type slides
pdf	product-type.pdf	r1	manage	137.8 K	2021-05-26 - 06:05	MarkusDemleitner	slides for the talk on product-types
pdf	voc-action.pdf	r1	manage	256.9 K	2021-05-26 - 06:05	MarkusDemleitner	Slides for vocabularies in action

This topic: IVOA > WebHome > IvoaTCG > ProgramPrepVirtualMay2021 > InterOpMay2021 > InterOpMay2021Semantics
Topic revision: r5 - 2021-10-27 - MarkusDemleitner