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[postprocessing]

I'm a bit puzzled about the shape of the velocity curve displayed, when I call track statitics.

I put the Samsung S9 smartphone (Android 10) into my car, started ORUXMAP's tracking and drove a highway at constant velocity of 50km/h using the electronic speed control for more than 10km. During this trip,  I continuously checked the measured speed not only with my car's tachometer but also digital numbers displayed by ORUXMAP's Trip-Computer.  The speed was verified by both tools to be continuous in a range of 50,0 +-0,5km/h.

• At the end of the trip I looked at the stored route's statistics, splitting the trip into a big number of segments. The table confirmed, that I never left the speed range of 50,0 +-0,5km/h. So far no surprise.
  



• !! But activating the graphics displaying the speed. I saw a curve undulating between 48km/h and 57km/h. !!
  

So I'm a bit puzzled, what happens to the speed data at their transformation into the graphic display? (Is there some postprocessing applied to the data (like smoothing) to generate the plot, behaving crazily)

Anybody out there, who ever checked the graphic display for correctness and precision?


(I did this check, because I had been puzzled by the graphic display of my speed during running, where I couldn't believe my speed was varying so much up and down during a long run)

Hi

Does anybody know the way Oruxmaps computes the velocities?

I guess, it is the distance between two positions divided by the time interval between the two position fixes.

My question is, how is this time interval defined?
In the GPS settings I can only set the time interval, defining the minimum time gap between two positions to be stored. But that might not be the time interval used to compute the velocity.
Probably there is another time interval used for velocity computing. Can that be modified?

[velocities]

After tracking a trip, positions, velocities stored also.
Opening a track through the Statistics button, velocities can be displayed as a table at adjustable distance averages and as a plotted line in a graph.

The positions look perfect. And if I stand at one spot for some time, position data slowly and continuously drift in an area of about 5m diameter.

What I find is, that the calculated velocity data in the line-plot are quiet noisy. I.e. running at a continuous speed of 10km/s generates a plot displaying deviation of +/- up to 2km/h, changing within a second.  That doesn't improve if I change the GPS-time interval oder GPS-distance interval for storing the data. As the modification of these intervals lenghts doesn't make a difference, I guess the velocities are not calculated basing on the time to distance ratio of successing stored locations.
So there are some questions arising from this:
  >> How is the velocity computed
  >> Is there an option in OruxMaps to smooth/filter/average velocity data, to improve the readability of the velocity-plot ?
  >> Does anybody else observe these scattering of velocities?
  >> In case OruxMaps cannot provide smoothed data, are there tools around to do so?

Further: The axis-scale of the line plots would be better readable if I could change the text height.

I'm using OruxMaps 7.4.22 at an Android 10 Smartphone.

Oruxmaps 7.4.22 + BRouter

After using Brouter to create a route, i get this route with lots of signs like (turn right, turn left) included into the map.
I would prefer to exclude these information and just get the dashed colored trackline displayed without these pictograms included. How can I avoid them? I found how activate distance marks, but not how deactivate these rouing signs.
Any idea?

best regards
Hans