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Re: how to forward RTCM data to gpsd?
From: |
Gary E. Miller |
Subject: |
Re: how to forward RTCM data to gpsd? |
Date: |
Sat, 12 Dec 2020 08:54:17 -0800 |
Yo Greg!
On Sat, 12 Dec 2020 08:24:48 -0500
Greg Troxel <gdt@lexort.com> wrote:
> "Gary E. Miller" <gem@rellim.com> writes:
>
> > Yo Greg!
> >
> > On Fri, 11 Dec 2020 20:19:44 -0500
> > Greg Troxel <gdt@lexort.com> wrote:
> >
> >> I wonder why you are only getting GPS from the local station, but
> >> presumabbly it's old and not sending Galileo and GLONASS
> >> corrections.
> >
> > RTCM 3 is GPS and GLONASS only.
Yes. My mistake, I meant RTCM 2.
> Perhaps in some trivial spec sense, but my local reference network is
> sending MSM4 format for other constellations. An update read:
>
> 7/10/19- RTCM 3.x (MSM4) single site products introduced. All
> RTCM MSM (Multi Signal Messages) now include GPS with L5, Glonass,
> Galileo and BeiDou.
Yes, a big part of RTCM 3, over 2, was the additional constellations.
> >> Repeating something I said earlier my local RTCM3 provider is now
> >> sending data on all 4 constellations.
> >
> > Not all 6?
>
> Which do you mean beyond GPS, GLONASS, Galileo and Beidou?
As defined by BNEA 4,11, from gps.h
* 1 = GPS 1-32
* 1 = SBAS 33-64, 152-158
* 1 = QZSS 193-197 Undocumetned u-blox goes to 199
* 2 = GLONASS 1-32, nul
* 3 = Galileo 1-36
* 4 - BeiDou 1-37
* x = IMES Not defined by NMEA
* 6 = NavIC (IRNSS) NMEA 4.11+
So NavIC, and QZSS.
> If you mean IRNSS and QZSS, those are regional, not global, and I do
> not hear of anyone receiving them in CONUS
I get QZSS in Oregon. gpsd has usrs that get NavIC.
> > I have run tests with GPS+SBAS and GPS only. Both using SBAS
> > correction. Adding SBAS to the fix decreases the fix quality.
> > YMMMV.
>
> I gather you mean "adding the SBAS pseudoranges".
Of course.
> I was talking about
> uncorrected pseudoranges from a bunch of satellites vs those same
> satellites
Never heard of that. Got a reference?
> and also using corrections that arrived via SBAS.
Which are just RTCM2.
> The onlu psue My
> impression, not rigorously confirmed, is that using the corrections
> helps.
My tests on u-blox 9 show otherwise. Feel free to send us your test
results.
> > Some do. Depending on your u-blox model ubxtool will tell your the
> > difference. Plain "used" means the ranges were used. The DGPS flag
> > is set if SBAS or RTCM corrections applies. So if you have no
> > local RTCM, the DGPS flag tells you if the SBAS corrections were
> > used. Indepene nt of the "used" flag.
>
> Make sense; perhpas it's not as confusing as I thought.
Of course. "Everything in math is either trivial, or false". :-)
RGDS
GARY
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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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- how to forward RTCM data to gpsd?, Kristoff, 2020/12/08
- Re: how to forward RTCM data to gpsd?, Gary E. Miller, 2020/12/08
- Re: how to forward RTCM data to gpsd?, Kristoff, 2020/12/09
- Re: how to forward RTCM data to gpsd?, Gary E. Miller, 2020/12/09
- Re: how to forward RTCM data to gpsd?, Kristoff, 2020/12/09
- Re: how to forward RTCM data to gpsd?, Kristoff, 2020/12/11
- Re: how to forward RTCM data to gpsd?, Gary E. Miller, 2020/12/11
- Re: how to forward RTCM data to gpsd?, Greg Troxel, 2020/12/11
- Re: how to forward RTCM data to gpsd?, Gary E. Miller, 2020/12/11
- Re: how to forward RTCM data to gpsd?, Greg Troxel, 2020/12/12
- Re: how to forward RTCM data to gpsd?,
Gary E. Miller <=
- Re: how to forward RTCM data to gpsd?, Greg Troxel, 2020/12/12
- Re: how to forward RTCM data to gpsd?, Gary E. Miller, 2020/12/12
Re: how to forward RTCM data to gpsd?, Martin Laabs, 2020/12/09
Re: how to forward RTCM data to gpsd?, Greg Troxel, 2020/12/09