IVOA and ADASS?

[Rob Seaman]

Hi Arnold,

> (2) Time is already properly defined in WhereWhen; why deviate from  
> that standard?

VO standards are driven by astronomical usage, not the other way  
around.  Also, I thought the broader view of STC within IVOA is as (in  
effect) a library to be called from within the other standards, rather  
than a wrapper to envelope them.

For VOEvent, the What element is used to describe the observation(s)  
(dependent variables) characterizing the event.  WhereWhen is  
primarily targeting information for follow-up observations (and this  
carries over into using STC to represent orbital elements).  WhereWhen  
also specifies a timestamp (independent variables) for the event.   
Realizing a timeseries as an element under What can then rely on the  
timestamp from WhereWhen to calibrate relative timings to an absolute  
scale.

If WhereWhen were to express timestamps in multiple systems, e.g.,  
topocentric/UTC and barycentric/TCB, then this might also resolve  
Roy's issue.  The relative timings from What could (for non- 
pathological cases) be recalibrated to match each system.

(I suspect to hear reasons why we care about cases I'm considering  
pathological :-)

Rob