Re: My GPS-receiver is too good 2

[Gary E. Miller]

Yo Håkan!

On Tue, 21 May 2024 21:41:01 +0200
Håkan Elmqvist <hakelm@smeden.org> wrote:

> Returning to this subject I am sorry being a bit slow but I simply 
> didn’t have the time.

No one here is in a rush.

> All the time I get the same position from the receiver, so I took the 
> receiver on a bike-tour resulting in a 10 MB json file. As you can
> see below I just got a single position in spite of many km pedaled
> (jq extracts the lat and lon fields, awk with seen eliminates all
> identical results):

No, I can't see below, as you failed to include your data.

You can get that this way:  gpspipe -R -x 30 > raw.log"

> If I, however, reset the receiver between observations I get a fresh 
> position every time and the values are very reasonable (extracting
> UTC, lat and lon with awk):

How do you "reset the reeciver"?

> root@pipickle:~# usbreset 1546:01a7
> 
> Resetting u-blox 7 - GPS/GNSS Receiver ... ok

Uh, what is usbreset?  That is no reseting the GPS, that is resetting
the USB connection.

Also, do you have a new model, or late model u-blox 7?  You should upgrade
to at least a verion 8, if not a versio 10.

> gpsd: 3.22 (revision 3.22), receiver u-blox 7 – GPS/GNSS (??).

Yeah realize that  gpsd 3.22 is really old?  Latest release is 3.25,
and 3.26 is not far away.

> What is the problem with this receiver, is there anything I can do or
> is it that simple that I have been deceived buying this cheap gadget?

First, update to 3.26, or git head, then send us a raw log capture.
And you can certainly do way better than a really old ublox 7.

> Ps Pls remember that the fourth fractional decimal digit of a minute
> in most places corresponds to 1/10000 Nautical Mile (1852 m) and is
> worth around 18 cm.

Yes, as shown here:

https://gpsd.gitlab.io/gpsd/gpsd-numbers-matter.html#_latitude_and_longitude

No way a 7-series is doing much better than 10m.

RGDS
GARY
---------------------------------------------------------------------------
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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    "If you can't measure it, you can't improve it." - Lord Kelvin

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