[time-nuts] sub-minute time-precision in court-case

[ken hartman]

This precisely why I stopped wearing a watch years ago....
Stranger: "What time is it?"
Me: "When?"
Stranger: "What 'when'? - now of course!"
Me: "Now - where? - Now you? or Now me? (Hint ~ 3 nsec dt)"
and so forth and so on.
better a watch don't have - no questions


On Tue, Sep 3, 2013 at 4:47 PM, Tom Van Baak <tvb at leapsecond.com> wrote:

> > Nowhere does the opinion mention if the timestamps were taken on
> > the same clock or if the two clocks were synchronized.
>
> PHK,
>
> Correct. This is an age-old problem, whether its minutes or nanoseconds.
> Time-stamps are inherently relative to a local oscillator's time and rate
> offset, and affected by frequency drift and stability levels.
>
> A solution to this problem is for the "first responder" to take the cell
> phone(s) and simultaneously send a text message to himself from each phone.
> That could help establish a legal time difference (unless, there are
> variable reception or carrier-specific delays).
>
> They could also simultaneously send cell phone photos of a handheld GPS
> receiver's time display. That could help establish a legal time accuracy
> question (unless, the cell phone or GPS receiver were in some sort of
> hold-over mode).
>
> For extra credit, further photos can be sent each hour for hours or days
> to determine the cell phone frequency drift and stability parameters.
>
> Then again, realize that a jury of your fellow citizens, not a jury of
> your "peers", will decide the question of timing. Thus to raise technical
> issues like syntonization vs. synchronization, or standard vs. Allan
> deviation, or GPS vs. UTC clocks will probably not help your case.
>
> /tvb
>
>
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