Bob,
Since the satellite orbit the earth with a period of 11 hours and 58
minutes, it is actually twice a day.
Cheers,
Magnus
On 10/20/2014 03:50 AM, Bob Camp wrote:
Hi
The GPS constellation repeats roughly once a day. It is not at all uncommon to
have a “worst case” sattelite geometry
The constellation may repeat at 12hr intervals , but at any static position you
will only see one per day , no? , the other being 180 degrees way. I only get
one regular bump.
Le 20 oct. 2014 à 09:43, Magnus Danielson a écrit :
Bob,
Since the satellite orbit the earth with a period of 11
Bob,
Since the satellite orbit the earth with a period of 11 hours and 58
minutes, it is actually twice a day.
Cheers,
Magnus
I've been reminded of that before, but the fact remains that here the
interruptions when they happen are at 24-hour intervals, not
Hi
Yes, but there’s this large object in the sky that modifies the ionosphere as
it travels in a “about one a day” track. It appears to be coming up just about
now, but I do need more coffee to be sure …
The combination of the constellation and the ionosphere are what I believe give
you the
Bob,
You mean the Sun, correct?
Regards,
John
On Oct 20, 2014 4:16 AM, Bob Camp kb...@n1k.org wrote:
Hi
Yes, but there’s this large object in the sky that modifies the ionosphere
as it travels in a “about one a day” track. It appears to be coming up just
about now, but I do need more
Hi
Gee, now after a few cups of coffee … yes that does appear to be the sun.
The GPS system does it’s best to model the ionosphere and transmit that data.
Unfortunately the model / model resolution is not as good as it could be. That
lets the ionosphere creep into the solution more than
having kept watch over oscillators for about half a century now... My first
assumption would be that a once-a-day bump in time offset or tuning word,
is due to earthside changes especially temperature of the earthside
oscillator environment.
Tim N3QE
On Sunday, October 19, 2014, Bob Stewart
On Mon, Oct 20, 2014 at 2:43 AM, Magnus Danielson
mag...@rubidium.dyndns.org wrote:
Bob,
Since the satellite orbit the earth with a period of 11 hours and 58
minutes, it is actually twice a day.
But then your house has only completed half an orbit.
--
Brian Lloyd
Lloyd Aviation
706
The GPS satellites are at an altitude that gives them an orbit of 12* hours.
But during that time the earth has made half a rotation. Thus it takes -two- SV
orbits and -one- earth rotation to get back to the same geometry. It is this
24* hour ground-track repeat time that is of interest in
kb...@n1k.org said:
The combination of the constellation and the ionosphere are what I believe
give you the once a day (rather than once per 12 hours) bump.
There is another layer. In addition to the normal once-a-day type
differences, the pattern of satellites drifts slowly from day to
Hi Bob Camp,
In your response to Chris, you said: Once you have it “right” you really need
to check it over a month or two to watch for GPS “once a day” issues.
Could I ask you what you meant by these once a day issues? Was this a
general comment, or was it about something specific? As you
that are DC
isolated from the antenna.
Bob
From: Bob Camp kb...@n1k.org
To: Bob Stewart b...@evoria.net
Sent: Sunday, October 19, 2014 9:01 PM
Subject: Re: [time-nuts] GPS once a day issues ?
Hi
One of the reasons you want to wide space antennas if you
Subject: Re: [time-nuts] GPS once a day issues ?
Hi
The GPS constellation repeats roughly once a day. It is not at all uncommon to
have a “worst case” sattelite geometry for a given antenna location. If you
have one, it will repeat once a day and show up as a bump in the timing out of
your GPS
Hi
The GPS constellation repeats roughly once a day. It is not at all uncommon to
have a “worst case” sattelite geometry for a given antenna location. If you
have one, it will repeat once a day and show up as a bump in the timing out of
your GPS module. If you track long term data, it will /
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