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Re: my total miserable failed experiment with PPP and rtklib
From: |
Gary E. Miller |
Subject: |
Re: my total miserable failed experiment with PPP and rtklib |
Date: |
Tue, 25 Jul 2023 12:33:28 -0700 |
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
Veritas liberabit vos. -- Quid est veritas?
"If you can't measure it, you can't improve it." - Lord Kelvin
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