DAL sessions in Victoria

Rob Seaman seaman at noao.edu
Wed Apr 26 06:19:22 PDT 2006


Sounds like Victoria is shaping up to be an interesting meeting.   
Polycom access?

On Apr 26, 2006, at 3:48 AM, Silvia Dalla wrote:

> STAP assumes some friendliness of Votable to
> ISO-6801 time strings
>
> I think that enabling some degree of interoperability between
> Astronomy and Solar System VOs is important. The science
> boundaries between these areas are becoming less and less
> sharp (Helio- and astero-seismology,

Well, that suggests an interesting use case.  I built observing  
infrastructure for the SONG asteroseismology project in the  
mid-90's.  This was an offshoot of GONG (Frank Hill was one of the  
principals) to take a long baseline of evenly cadenced spectra of  
Procyon.  There was an ADASS paper (Charlottesville, I think).

The complications for temporal searching are several.  First, you  
need to be able to search in a barycentric (or arbitrary) time  
system.  Second, you need to be able to search through some sort of  
evenly gridded comb filter in cadence - something like "return all  
images/spectra whose mid-exposure occurred near an even quarter- 
hour".  Third, you have to be able to specify "near" - "within a  
window of plus or minus one minute".  Fourth, you may need to be  
sensitive to some very creative observing modes and data structures.   
SONG also experimented with a multiple ramped exposure mode for  
acquiring a time sequence of spectra in a single exposure.  Makes me  
wonder further about searching for off-band data from dual exposure  
nod-and-shuffle observations from instruments such as MARS on Kitt  
Peak.  The second field is shifted both spatially and temporally  
(interleaved as with any chopping or beam switching mode).

ISO 8601 provides (as a central design feature) a simple way to  
specify cadences on a wide range of timescales, i.e., so many seconds  
or tens of seconds, minutes, hours, days, (even weeks, I believe),  
months, years, centuries, etc.

Just thought I'd toss all that astronomical succotash into the rich  
cybernetic stone soup that's simmering on the virtual back burner.

> I believe that Frank and VSO have expressed an interest in
> IVOA activities, specifically VoEvent.

VOEvent certainly intends to be able to represent solar transients.   
Think everybody benefits if our tools are built to serve both  
nighttime and daytime astronomy.  The more fundamental distinction is  
between synoptic data sets and (what's the antonym?) "selective",  
"serendipitous" or "classically observed" data sets.

Rob



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