Re: best gps receiver for time synchronization

jack wrote:
Hi all,

I am trying to sync my Windows box to an external GPS source. I
currently have BU353, whose output is not very periodic. I read up on
ntpd implementation that uses PPS signal but I don't even have an RS
232 port on my computer.

My questions:
1) what's the best GPS antenna (and protocol) in terms of
consistencies in its output?
2) what kind of accuracy can i expect?

Thanks to all.

Jack

Jack,

I recently wanted to add a serial feed to a PC but, like your PC, there was no serial port. In my case, I could choose a different PC, but I could have bought a PCI serial card (which seem to be quite rare, now).

I don't know if anyone has written a driver which will suit your USB-based BU353.

As to accuracy, I've been helping Dave Hart test a new NTP port for Windows, and on my PC I'm seeing reported offsets typically less than 300 microseconds from a serial and PPS GPS device (Garmin GPS18 LVC), and there is strong evidence that the variations are temperature related, as the PC is in a domestic environment, and the reported offset correlates well with the ambient temperature.

http://www.satsignal.eu/mrtg/feenix_ntp_2.html

That type of device will give better accuracy than a USB-connected GPS, and it needs no external antenna.

Cheers,
David

.

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