[Even list/ event ] stabilizing the name of a data set containing lists of events

[Mathieu Servillat]

Hi all,

 From what Stéphane said, it is again clear that an event is a too large 
concept. Al least, we may all be talking about "transient celestial 
events" in the VO (as written in 
https://www.ivoa.net/documents/VOEvent/), then there are maybe domain 
specific events: solar event, impact of a comet on a planet...

This implies that if we define "event-list", then it may not be the 
exact same meaning as a "list of events". Also, it seems that an "event" 
is not a data product, but there may be data associated to an event 
(such as images, spectra... or event-lists!).

For the definition of an event-list data product, it would be fine for 
the high-energy domain as it is the name commonly used, but it may need 
a clarification:
"A row in an event list is typically characterised by spatial, spectral, 
and time information."
--> this suggest that the information could be a range of values, but we 
are here talking about one value only.
Maybe replace by:
"... characterised by a spatial position, a time and an energy."

Cheers,
Mathieu


Le 25/07/2023 à 11:03, Markus Demleitner a écrit :
> Dear Stéphane,
>
> On Mon, Jul 24, 2023 at 05:02:12PM +0200, Stéphane Erard wrote:
>> If I remember correctly, the EPNCore definitions were adapted from
>> VOevents at the time of writing.
> I hadn't noticed this before, but yes, the "event" in "VOEvent" is at
> best loosely connected with the "event" in the event lists common in
> astropatricle physics.  Well, we're doing (semi-) formal semantics to
> try and get a grip on these ambiguities by selecting concepts, giving
> them some (hopefully intuitive) label and then defining them as
> precisely as we can (in a few words).
>
>> - I think event_list is ambiguous —in my opinion, this refers to
> Well, it's up to us to disambiguate it -- our
>
>    http://www.ivoa.net/rdf/product-type#event-list
>
> preferably should be what sufficiently many people think is an "event
> list", but in the end it is what we define it to be.
>
> Given that there is a fairly large community that calls sequences of
> possibly incomplete (time, direction,energy) tuples of detected
> particules "event list", I'd say that's the terminology we should
> adopt unless it is *seriously* misleading in one or more other
> communities.  So... is there conflicting usage of something like
> "event list" in the solar system community?  If not, I'd say we can
> risk claming the term for some slight generalisation of the concept
> the astroparticle folks give us.
>
>> => I would reserve "event" for the actual event, and call
>> observations of this event something like event_observation, with
>> an ID potentially connecting them to the event (which allows
>> finding all identified observations of the event easily).
> Let's delay the discussion of what an "event" would be within
> product-type (or even beyond) to when someone wants to store either
> VOEvents (for which I'd like Mathieu's suggestion of event-alert) or
> (time,direction,energy) tuples or still something else in Obscore --
> or wants to distribute that kind of thing in Datalink.  I think it's
> a lot easier to discuss this when there's an actual use case.
>
> So... if this manages to mollify Stéphane's concerns (does it?) and
> nobody else protests, I'd go ahead and change
>
>    http://www.ivoa.net/rdf/product-type#event
>
> to
>
>    identifier: event-list
>    Label: Event List
>    Description: A collection of observed events, such as incoming
>      high-energy particles. A row in an event list is typically
>      characterised by spatial, spectral, and time information.
>
> Comments?
>
>           -- Markus

-- 
Dr. Mathieu Servillat
Laboratoire Univers et Théories, Bât 18, Bur. 222
Observatoire de Paris, Site de Meudon
5 place Jules Janssen
92195 Meudon, France
Tél. +33 1 45 07 78 62
--