Re: my total miserable failed experiment with PPP and rtklib

[Gary E. Miller]

Yo Greg!

On Tue, 25 Jul 2023 15:26:32 -0400
Greg Troxel <gdt@lexort.com> wrote:

> "Gary E. Miller" <gem@rellim.com> writes:
> 
> > On Tue, 25 Jul 2023 14:56:26 -0400
> > Greg Troxel <gdt@lexort.com> wrote:  
> 
> >> Huh?  SBAS is not "assisted GPS".   It is space-based augmentation
> >> service, and is the general concept of which WAAS (US) and EGNOS
> >> (EU) are specific systems.  
> >
> > What it "augments" is startup, and failure detection, not accuracy.
> > This is why recent receiver, like the u-blox 9, do not bother to
> > listen to SBAS anymore.  
> 
> https://gssc.esa.int/navipedia/index.php/SBAS_Fundamentals
> 
> With dual frequency, differential is far less important, because
> errors are mostly about tropo delay.

Which is what I said, no accuracy improvement for newer receivers.

> Later firmware revs of F9P
> added back SBAS.

Yeah, because ICAO.  They oversee WAAS.

> On my (older, L1 only) garmin etrex, I get the D icon per satellite
> when it gets corrections from WAAS.

Boy, is that a can of worms.  No two receeivers seem to handle the DGPS bit
the same way...

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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