[LEAPSECS] it's WP7A week in Geneva

[M. Warner Losh]

In message: <B1B3DBCA2C4940318EFFE54DC99D4B55 at pc52>
            "Tom Van Baak" <tvb at leapsecond.com> writes:

: > I've got a GPS receiver here. It reports UTC so, I presume, uses a stored

: > delta until it picks up a new one. For the uses I have for it, an error of

: > 1 or even 5 seconds (but not 30) is far more useful than "no data".

: 

: Clive,

: 

: Or it may be hard-coded; how do you know for sure? OK,

: in your case you don't care; but not all cases are that easy.

: 

: This is the crux of the problem: you write "I presume". In my

: experience, GPS receiver manufacturers don't know or don't

: tell how they handle all the edge cases of getting UTC from

: GPS time. So users who need ultra-reliable UTC from a GPS

: receiver either have to guess, or actually test all the obscure

: cases. This is non-trivial, given that real-life tests only happen

: once every year or two.


I'm sure that the folks who have it working have good access to
simulators.  I'm also fairly sure that more than half of the gear out
there will fall over dead for a negative leap second...

Warner