[ntp:questions] .1 Microsecond Synchronization
Richard B. Gilbert
rgilbert88 at comcast.net
Thu Jun 4 19:03:18 UTC 2009
Terje Mathisen wrote:
> John Hasler wrote:
>> ScottyG writes:
>>> Has anyone had any experience doing this? Can anyone suggest how to
>>> achieve this accuracy?
>>
>> Talk to the very long baseline radio astronomers.
>>
>>> We do have some budget but this but if I need to spend a whole lot on
>>> this I need to get in front of my management with the reasons.
>>
>> You will need to. Has someone already gotten in front of them with the
>> reasons for this accuracy?
>>
>> Of course, recording timestamps with 100 nanosecond _precision_ is easy.
>
> That is probably the real requirement:
>
> Windows' os clock runs with 100 ns ticks, but the actual resolution and
> accuracy is normally 10-17 ms.
>
> That said, yes you can get down to sub-us timestamps, but it requires
> dedicated hardware to do so:
>
> First you must have a timing-optimized gps receiver, then you need some
> hardware which can be slaved to the pps signal from that gps, and which
> can also be used as the time base of all your logs.
>
> I.e.a PCI card or similar which your apllications can query directly to
> get the current timestamp.
>
ISTR that both Symmetricomm and Meinberg Funkurhren offer such cards at
prices somewhere betwen $1250 and $2500; IOW they are not cheap!! I
believe that both support an optional GPS receiver. For more money, of
course!
More information about the questions
mailing list