Registry in RSS

[Dick Shaw]

Without disagreeing with the fine ideas offered in this thread, I think there 
may be some value in keeping the conceptual basis and purpose of VOEvent 
relatively uncluttered. The example notification from IERS is, in its content, 
really about a non-event (no adjustment to the time reference system is 
expected to happen at the end of June). A notice about the availability of a 
new VO resource, while interesting, isn't exactly an event in an astronomical 
sense. Are these notifications really what VOEvent about? At first blush I 
would have thought them more appropriate to a news feed.

My $0.02.

-Dick

On Thu, 14 Jan 2010 07:08:38 -0700
  Rob Seaman <seaman at noao.edu> wrote:
> On Jan 13, 2010, at 12:43 PM, Mike Fitzpatrick wrote:
> 
>> Not quite what I meant:  I know there are numerous feeds for actual 
>>"VOEvents", what I was proposing was a feed for "VO Events" like the 
>>availability of a new resource, overlaying the voevent infrastructure, e.g. 
>>not that the Catalina Sky Survey found an object, but that the CSS is now a 
>>broker for "Bob's-really-cool-GRB-followup-on-his-GalileoScope" program.
>> 
>> The heretical part is that I see 'events' as a type of message, and little 
>>difference between a GRB "stream" subscription, a "KBO" one, and a "general 
>>msg" one.  Is the idea "there is something new on the sky" really that much 
>>different than "there is something new in the Registry"?  Note I'm not quite 
>>yet suggesting IVOA address these cross-WG issues, neither do I see a need 
>>for an emerging discussion on a new protocol for Tweet/Rss that shares many 
>>similarities (at least wrt the 90/10 rule) with existing standards.
> 
> As a timely example of such an astronomical, but not celestial, event see 
>the appended IERS bulletin published this morning.  This shares numerous 
>features with the mechanism that Mike is describing.  It cries out for a 
>semantic representation (rather than "natural language") - such as an XML 
>standard like VOEvent.  (And an early debate in the WG was whether "event" 
>had a strictly celestial meaning or also included, for instance, the computer 
>science definition of events.)
> 
>Further, it is prospective, rather than retrospective - VOEvent has to be 
>able to describe events that haven't happened yet, in addition to reports 
>from the historical record.  A repository of past bulletins is implicit.  It 
>has an author (Gambis) as well as a publisher (IERS).  Delivery is transport 
>neutral.  There are contingent metadata like the publication date and the 
>publisher's contact information.  The message relies on several widely 
>promulgated standards, most notably UTC.  Etc.
> 
> A field of inquiry is layered on many such streams of events, whether 
>"event" is defined scientifically, technically or simply logistically.  Does 
>it make sense to invent a new representation and transport protocol for each 
>stream?  More likely there will evolve a small number of options that satisfy 
>that 90/10 rule.  Some applications are so idiosyncratic or tightly bound 
>that they fall into the 10%.  But too often a 90% project chooses a 10% 
>solution for no good reason - or they choose a too broad solution (such as 
>the text file below) that is no real solution at all.
> 
> Is Mike's heresy a high priority for IVOA attention?  I don't know, but it 
>does seem like a good topic for the TCG workshop whenever and wherever that 
>may ultimately be held.
> 
> Rob
> ---
> 
> Begin forwarded message:
> 
>> From: IERS EOP Product Center <services.iers at obspm.fr>
>> Date: January 14, 2010 5:44:21 AM MST
>> To: adresc1 at arcas.obspm.fr
>> Subject: Bulletin C number 39
>> 
>> 
>> 
>> 
>>     INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) 
>> 
>> SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE
>> 
>> SERVICE DE LA ROTATION TERRESTRE
>> OBSERVATOIRE DE PARIS                                   
>> 61, Av. de l'Observatoire 75014 PARIS (France)
>> Tel.      : 33 (0) 1 40 51 22 29
>> FAX       : 33 (0) 1 40 51 22 91
>> Internet  : services.iers at obspm.fr
>> 
>>                                               Paris, 14 January 2010
>> 
>> 
>>                                               Bulletin C 39
>> 
>>                                               To authorities responsible 
>>                  
>>                                               for the measurement and 
>>                                               distribution of time 
>>            
>> 
>> 
>> 
>>                          INFORMATION ON UTC - TAI
>> 
>> 
>> NO positive leap second will be introduced at the end of June 2010.
>> The difference between Coordinated Universal Time UTC and the 
>> International Atomic Time TAI is :		
>> 		
>>     from 2009 January 1, 0h UTC, until further notice : UTC-TAI = -34 s
>> 
>> Leap seconds can be introduced in UTC at the end of the months of December 
>> or June,  depending on the evolution of UT1-TAI. Bulletin C is mailed every 
>> 
>> six months, either to announce a time step in UTC, or to confirm that there 
>> will be no time step at the next possible date.
>> 
>> 
>>                                           Daniel GAMBIS
>>                                           Head			
>>                                           Earth Orientation Center of the 
>>IERS
>>                                           Observatoire de Paris, France