Re: my total miserable failed experiment with PPP and rtklib

[Gary E. Miller]

Yo Hans!

On Tue, 25 Jul 2023 20:11:17 +0200
Hans Mayer <gpsd@ma.yer.at> wrote:

> On 24.07.23 23:12, Gary E. Miller wrote:
> > That sounds about right.  But no need to calculate, just use
> > gpsprof.  
> 
> I have 12 independent measurements done with "gpsprof" and therefore
> 12 *.plot files. How can I calculate the distance between each of
> them with "gpsprof" ?

All the stats that matter are at the bottom of the plot.  Assuming you
are using the current version of gpsd.  If you want to measure between
two points on the plot, just use a ruler, the plot is linear.

> > As above, best to just post your gpsprof png.  
> 
> Attached there is one of these 12 results.

Looks normal.  CEP(50) of 0.753 meters.  Minimum 41 sats in each
fix, so good skyview.  I'd look at the polar plot to verify that.

> >   Better to use a PPP
> > service.  Much better.  
> 
> This I tried. But I never got a result. We discussed this already
> here in this mailing list.

Works for me.  Not sure what your problem is.  We do know that
getting a PPP result involves more than a little luck.

> > A good base should be less than a km from you.  How far is your
> > base?  
> nearest is 40 km, the next is 220 km and more

WAY too far away to be useful.

> In Austria there is the APOS system available. It's from the
> government and commercial.
> 
> https://portal.bev.gv.at/portal/page?_pageid=713,3175360&_dad=portal&_schema=PORTAL

Give it a try.  It may need the "send GGA) option, which someday we'll 
implement.

> If I remember correctly there are about 37 base stations in a grid of 
> about 50 km distance and the offer a position in the sub-cm range.

Everytime I try to get someone to prove "sub-cm" they disappear.

> > There may be better places, but some people here still use it.  
> 
> I don't want to misuse  this mailing list.

It's not like it is high traffic, and IMHO on topic.

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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