[LEAPSECS] Violins and sunspots

[Rob Seaman]

I said:


>> First, astronomers "at large" continue to use UTC widely for almost  

>> every conceivable purpose - it is precisely that UTC remains a  

>> flavor of Universal Time that permits this.


Steve Allen wrote:


> It's much simpler than that.  [...]  We use UTC because that is the  

> internationally approved name for the broadcast time scale


Really, both the logistics of delivery, as well as UTC's definition as  
a flavor of mean solar time matter here, for instance:


> The LIDAR community and some geophysics folks have chosen GPS  

> because that is another broadcast time scale which can be expected  

> to be available to every measurement system with above-ground  

> components.


And many telescopes rely on GPS receivers as standard references  
(independent of NTP strata) because of the logistical convenience.   
New telescopes such as LSST (http://www.lsst.org) may even consider  
making this an explicit requirement.  (I was in the meeting.)

UT remains an intermediate time product, however, independent of how  
the time signals arrive.  The need to sync systems slaved to GPS with  
systems slaved to NTP likely *also* places UTC related requirements,  
but lots of astronomical code (independent of recent IAU standards)  
remains dependent on Universal Time (mean solar time) itself.

Why shouldn't a one word proposal, "GPS", be sufficient for ITU-R TF. 
460 (v2.0)?  Release Universal Time into the wild to compete on its own.

Rob