[LEAPSECS] Skepticism

[Ian Batten]

On 31 Dec 2010, at 06:31, Rob Seaman wrote:


> My reading of TF.460-4 is that the limit could lengthened to +/- 3.0  

> seconds (30 emphasized ticks each way) without sacrificing the  

> actual *radio* mechanism (that it seems to me is the only thing  

> truly in the purview of ITU-R).


Although there are national time signals that can only cope with with | 
DUT1| < 1s: the UK one, for instance.  So if |DUT1| > 0.8s the UK  
signal can either be used to recover UTC, or UT1, but not both.    As  
MSF is funded to deliver UK legal time, that might make life very  
interesting.

Modifying the signal would be possible.  For example, as DUT1 is  
encoded in base-1, over sixteen bits, you could encode +/- 32767s at  
0.1s resolution and only break existing DUT1 consumers.   But that  
would require a census of how many devices are actually using the  
existing DUT1 format, and round the houses we go again.

ian