Re: Virtual Reference Stations (Was Re: gpsprof: higher resolution)

[Gary E. Miller]

Yo John!

On Mon, 24 Aug 2020 15:08:25 -0400
John Ackermann N8UR <jra@febo.com> wrote:

> On 8/16/20 7:19 PM, Gary E. Miller wrote:
> 
> >> That's one reason why I'm interested in trying the ODOT reference
> >> network in the hope that they will provide correctsions for GLONASS
> >> as well as GPS.  
> > 
> > ODOT does GLONASS, but only in a "virtual" ntrip that gpsd does not
> > understand and no one can show me what messages are required.  
> 
> Just a follow-up information point:
> 
> I got a login to the Ohio DOT virtual reference station network,
> which uses the Trimble VRS system.

Interesting.  ORGN (allied with a different ODOT) uses Leica.

> It appears the only unique
> requirement is that the rover needs to send an NMEA GGA sentence to
> provide an estimated location used to construct the virtual reference
> station location.

Yes, old news.  But exactly how must that be sent to the daemon?

Maybe you can aks them?  The ORGN people don't know.

> Other than that, the traffic flow is all outbound
> from the network to the rover.  (I don't know if it needs just a
> single GGA sentence at login, or at some interval.)

Nobody seems to know.  No documentation we can find.  

Maybe you could grab a tcpdump of that traffic?

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  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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