Re: Hard or soft?

[Gary E. Miller]

Yo Håkan!

On Thu, 28 Mar 2024 21:42:49 +0100
Håkan Elmqvist <hakelm@smeden.org> wrote:

> it is encouraging to see that there still exists people who know
> their ways.

Geybeards don't die, they just afde away...

> My gpsd is:
> he@x22:~$ gpsd -V
> gpsd: 3.22 (revision 3.22)
> running on ubuntu 22.04 installed with apt a day before writing to 
> gpsd-users.

Ugh.  3.25 is current, and git head way bettter than 3.25.

> Do you believe that getting a later version, say gpsd-3.9.tar.gz will 
> fix this little problem.

3.9 is really, really, old.

> When I bought this device, must have been around 2004, I used it on
> my boat with a Windows computer without any problems.
> Now the Russians are tampering with our GNSS, so I thought I would
> just use the device to continuously monitor GPS-quality.

GPS anti-jamming tech is rapidly evolving.  Newer GPS will give you
much more data about any jamming you may see.

The chip makers don't tell us much about what they do internally about
jamming.  Externally researchers are trying various thing.

One approach is to take a time series of one datum.  Say like SNR over
100 seconds.  Then try to detect any odd trends in that data.  Say like
a jump, or steep ramp, in the data.  People are trying different length
of time series (100 seconds? 10 minutes?) over various datum (SNR, psuedorange,
latitude, etc.)  No reports of great success, and, of course, testing is
hard.

Newer GNSS receivers expose a lot more data so better suited to this
approach.

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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