Greetings

I know that the accuracy of GPS degrades indoors. However, suppose
that I just want to turn a GPS module on, acquire the current time
accurate to a second, and then turn it off. I can get a good deal on
the U-Blox LEA-5H modules (same as used on Arduino shields I think),
which have a high sensitivity, and I can use an active antenna if
needed.

Am I wasting my time. Sorry for not requiring the time more accurate
than a second, but that's all the clients require.

Tom Harris
=========================================================

Tom,

If the GPS has a battery backup, then you might get re-acquisition within less than 30 seconds of powering up. That's approximate with a u-blox NEO-6M on the top floor of a two-storey building, about 1/3 the way into the room, so most of the signal is through the roof.

Without battery backup, the acquisition time might be a lot longer (15-20 minutes), or even worse (hours) with a different GPS module which needs a much stronger signal to acquire than to track. The one which took hours had a 15 mm square patch antenna (AdaFruit), versus the 25 mm square antenna on the u-blox board I had.

The two units I am comparing are shown on my Web page here:

 http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html

although it's down right now. I quite accpet that other folks may have different results (or if "indoors" is next to a window!).

Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk

_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Reply via email to