How Can A Weak Cons...
 
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How Can A Weak Constellation Improve Your Position?

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(@paul-in-pa)
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Maybe I am too strong on Geometry, but how can a weak "other constellation" position improve your GNSS position?

Assume you have 10 GPS and 8 Glonass, what good are 3 Compass and 3 Gallileo satellites in improving your precision? Even with 4 each you are looking at PDOPS in the 5-7 range

Not having full GNSS software, how is the position of various constellations weighted in a final GNSS solution?

How precise are other constellation broadcast orbits and how precise are their related ephemeris? How timely are their post observation ephemeris?

I can imagine that the other satellites are in favorable positions, but imprecise ephemeris could give a mathematically tight solution that is in fact not accurate.

Paul in PA

 
Posted : February 3, 2017 9:59 am
(@nate-the-surveyor)
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I thought you were going back to the old days of 8 channel receivers.
If there were 12 birds in view, and one "base" reciever was in the field, it had an alogrithm, to ignore the 4 highest in the sky.
Then 2 more recievers were in the woods. Good sky view, from 30 degrees up from the horizon. This forced it to collect the highest birds. So, it only had 4 birds in common... So, the 2 woods units would fix well. But the one in the field, to the ones in woods, were poorer.
Just depends on their sky view.
N

 
Posted : February 3, 2017 2:28 pm