Re: Is speed required?

[Gary E. Miller]

Yo Владимир!

On Fri, 3 Apr 2020 14:46:00 +0300
Владимир Калачихин <address@hidden> wrote:

> Do all receivers always return speed and direction along with 
> coordinates? Can it be that there are only coordinates with 3D fix?

There are so many different receivers that generalizations are hard.
Many receivers are optimized for time, not position, and don't even
report any position at all.

And it gets more complicated.  gpsd will try to compute missing values
so the client does not have to.  So if your receiver only sends position
data, then gpsd will compute the speed for you.  This can be
confusing when gpsd computes one speed, and in the same cycle the
receiver sends a different speed.

This is another reason why clearing fix data at each cycle is so
important.  If stale data is used in computations then the results will
be un-good. 



RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

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    "If you can't measure it, you can't improve it." - Lord Kelvin

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