Re: [gpsd-users] Will proprietary NMEA extensions be included in gpsd?

[Gary E. Miller]

Yo Svenn!

On Sat, 27 Jun 2015 00:24:40 +0200
Svenn Are Bjerkem <address@hidden> wrote:

> I do not have much knowledge about the fine math of GNSS. I just saw
> an report from gpsd on unsupported message on my new GNSS setup.

GPS tend to throw out all sorts of redundant messages.  That way marketing
can brag that they do something another vendor does not.  We support
that which people find usefull.

> http://web.pdx.edu/~jduh/courses/Archive/geog481w07/Students/Franczyk_RMSE_Accuracy.pdf
> 
> http://www.leb.esalq.usp.br/disciplinas/Molin/leb447/Arquivos/GNSS/ArtigoAcuraciaGPSsemAutor.pdf
> 
> talking about the correct thing? I guess you guys know more about
> this, but I want to make sure I read myself up on the right thing.

Pretty sloppy, RMS error is a bunch of errors lumped together.  HDOP,
VDOP, PDOP, and TDOP break out the error components.  In particular
HDOP is usually much worse then PDOP, which is a good thing if all
you care about is your position on the surface.  Not so good if you
are in an aircraft.

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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