[time-nuts] I thought GPS repeated every 12 hours (-2 minutes)

[Bob Camp]

HI

The gotcha with anything local is the sidereal day repeat pattern The local stuff would have to 
be very solar oriented to be slipping at exactly that rate over a few months of data.  My guess 
is that when *this combo* gets into *that position* and *this multi path* happens … you get a 
glitch. It’s not there for long, but it is there. 

Credit where credit is due … some guy named Tom (who also drives around with 6 5071’s on 
a regular basis … handing them out to strangers) spotted the sidereal day time slip. I had been 
chasing it as if it was 24 hours and some weird local “train goes by an midnight” sort of thing. 

Bob


> On May 24, 2016, at 7:15 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
> 
> 
> kb8tq at n1k.org said:
>> The glitches are to narrow (short duration) and far to regular for the
>> ionosphere to be the issue.  
> 
> Is multipath from a large airliner in a landing pattern likely to cause that 
> sort of problems?
> 
> I'm 20+ miles off the end of SFO, but it's common to see large planes going 
> over and turning to line up for a landing.  On my one-of-these-days list is 
> to grab the airline location data and see if it correlates with GPS glitches.
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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