Re: satellites used - NMEA feed

[Gary E. Miller]

Yo Nick!

Glad to help.

On Wed, 29 May 2024 11:13:49 +0100
Nick Taylor <nicktaylor@dataskill.uk> wrote:

> Hi Gary
> 
> Thought I'd post this to list (following several private exchanges)
> 
> Many thanks for all your help - using your fixed release and with
> code revamp according to your suggestions seems we are now getting
> beautiful usat count from NMEA feed that isn't including satellite
> SKY records.
> 
> Thanks for all your hard work on this and patience with our 
> understanding of gpslib usage!
> 
> Best regards
> 
> Nick & team
> 
> 
> On 10/05/2024 20:40, Gary E. Miller wrote:
> > Yo Nick!
> >
> > On Fri, 10 May 2024 13:14:48 +0100
> > Nick Taylor <nicktaylor@dataskill.uk> wrote:
> >  
> >> Could you cast your memory back to Dec 2022 - we found that using
> >> NMEA feed we weren't getting satellite data although there was used
> >> satellite count available...  
> > Yeah, Sats Seen and  Sats Used just gets worse and worse.
> >  
> >> You kindly made a patch to pick this up as used satellite count if
> >> the satellite data wasn't available (see screenshot attached)  
> > I can'read read your screenshot, my eyes are going bad and that is
> > way to grainy for me to read.  And I certianly can't cut/paste the
> > commit number from a course image.
> >  
> >> On recently upgrading to latest gpsd release it seems that
> >> something has changed that makes used satellite count disappear
> >> again - we pick this up from gpslib variable
> >> gps_data_t.satellites_used  
> > And it is only going to get worse.  Newer receivers can never seem
> > to report sat counts consistently.  I have one receiver here that
> > reports 4 different sat counts in the same epoch.  Which is correct?
> >
> > This gets more complicated when the receiver can pick up 3 signals
> > (L1, L2 and L5) from the same sat.  Should that be reportd as 1
> > sat, or 3? For now, gpsd leans to reporting 3, except that not all
> > new multi-frequency receivers report enough data to know which is
> > which. 
> >> I'm also attaching output from gpspipe -R  
> > That looks good.  I'll play with that today.
> >
> > 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
> >  
> 
> 




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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