[ntp:questions] Re: Oncore driver in 4.2.0

Wolfgang S. Rupprecht wolfgang+gnus20031120T114922 at dailyplanet.dontspam.wsrcc.com
Thu Nov 20 19:56:27 UTC 2003


hmurray at suespammers.org (Hal Murray) writes:
>>In an urban canyon you may never get a low DOP... but what you describe
>>is a half-canyon and may not be too bad.
>
> A half canyon is probably better than a whole canyon.
>
> I was interested in systematic errors.  Suppose I collect a bunch of
> data and filter out the ones with poor DOP.  Maybe the position
> reported will be biased because the remaining data is mostly when
> the satellites are to the west.

I just did a multiday position survey (7.8 days so far) and it sure
looks like the most of the gps offset from it's average position
repeats on a daily basis.  I didn't expect this result.  I would have
thought that most of it was white-noise and averaging could reduce it
to nothing if one was willing to wait long enough.

   http://www.wsrcc.com/wolfgang/gps/gps-wander.png  (54k)

What is amazing is the amount that the offsets track on a day-to-day
basis.  Next, to find out the exact difference between sideral and
solar day and correct for that in the overlays.  I bet that will take
care of at least some of the horizontal smearing of the graph.

-wolfgang
-- 
Wolfgang S. Rupprecht 		     http://www.wsrcc.com/wolfgang/
       The above "From:" address is valid.  Don't mess with it.



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