-----Original Message-----
From: Hal Murray
Sent: Wednesday, October 10, 2012 5:37 PM
Unless your internet connection is really crappy, it will be better than a
serial (non PPS) connection from a low cost GPS unit.
There is huge (ballpark of 100 ms) wander on the serial output of all the
low
cost units I've tried. I say wander rather than jitter because it is very
low frequency. You can't filter it out by averaging over a small number of
samples.
You can get worse problems from bufferbloat on slow DSL lines. All it takes
is a big/long download.
======================================
Agreed on the USB, Hal, which is why I said "very bad (Internet
connection)". On the other hand, I have seen people reporting errors of
hundreds of milliseconds with Internet connections, so USB non-PPS may be
better than that.
If you're really lucky, your serial-USB convertor may carry the DCD line and
then you can get really significant gains. Not as good as a real serial
port, of course, but better than a LAN connection in my tests.
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: [email protected]
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