[time-nuts] nuts about position

[Bob kb8tq]

Hi


> On Jun 3, 2018, at 7:35 PM, Mark Sims <holrum at hotmail.com> wrote:
> 
> As far as I'm concerned anything that you can do to improve the position accuracy,  environmental changes,  noise environment, etc is a good thing.   Minimizing errors and disturbances can't hurt and may even improve things.  How much any improvement  provides ... ???   But  time nuts tend to be a bit nutty about minimizing our therbligs  ;-)
> 
> Most receiver self-surveys seem to get your lat/lon to the 2-3 meter range.   Heather's median survey is in the 1-2 meter range.  PPP data is in the < 0.25 meter range... seems like something worthwhile.  (altitude errors are usually around twice the lat/lon error).
> 
> There is always the possibility that some receiver model's computation of lat/lon/alt could have some intrinsic bias in it.   If so,  a position calculated by an external source could possibly degrade performance... 

If you go back to the NIST papers where they were testing timing modules, they indeed did find “gotcha’s” with putting in survey based coordinates. 
I don’t think they ever did PPP on the modules they published data on.

Bob

> 
> ----------------
> 
>> Is this applicable to a Thunderbolt, and would this improved position
> accuracy be expected to improve the time accuracy from a Thunderbolt
> compared to using the older Lady Heather 24 hour self survey method?
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