Speed values are incorrect

[framesfree]

Since the introduction of the color-coded routes I noticed that the speed value that is shown on the map per point was strange. I didn't notice it right away since I though that maybe I was really slow in the traffic.
However, today I was reviewing the data and discovered that I was going around 22 kph on a highway when I distinctly remember going around 80 there. I thought maybe it is Dawarich iOS client issue but I opened up my data from google takeout and here for instance it shows 35 km/h on a highway:

I opened up the data (My data -> Points) and found those points that roughly correspond to the screenshot above:

Speed, km/h	Recorded At		Coordinates
33		15 Apr 2025, 09:53:09	49.5030488, 6.1521719	
34		15 Apr 2025, 09:53:42	49.508576, 6.1645845	
33		15 Apr 2025, 09:54:08	49.5105568, 6.17637	
22		15 Apr 2025, 09:54:43	49.5070466, 6.1903454	
27		15 Apr 2025, 09:55:11	49.5075086, 6.1995048

Simple calculation based on position shows that I was moving with the average speed of 109.8 kph and dawarich average is 30.5, which is 3.6x slower. Maybe there is a conversion issue in the units somewhere? The real question is how those numbers are calculated. I also checked the raw takeout file and it seems that the speed is not logged there. Maybe it's just my instance? Can anyone try to reproduce this?

My setup
Dawarich is running on a VPS with docker compose (arm64/v8). "Default" dawarich_db "postgis/postgis:17-3.5-alpine" container is replaced (due to lack of support for arm64) with "postgres:17" + postgresql-17-postgis-3 installed.

Version
Currently - 0.27.1. I am pretty sure the speed was showing correctly for this trip before, but I don't remember which version it was - for sure before route color coding but I also migrated to arm64/v8 since then.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Map'
2. Load any route and hover over a datapoint
3. Note the 'Current speed' value

[TheBig-O]

I'm also experiencing this issue. My settings are for imperial values and the values are wildly off. It appears that it is considering "stop" points that are several hours later than what actually took place. In the image I uploaded, I was driving on a 50 MPH roadway, and it shows 15mph. IT also shows a duration of six and a half hours, but I was in the car for a total 12 minutes only.

[Kiriyashiki]

Same issue here. The real speed is around 110 km/h.

On version 0.27.2, unit set to km/h, points recorded by Owntracks. This seems to affect all points in my database and not just recent ones.

[framesfree]

I've proposed a pull request to fix it:
#1322
Works on my instance, let's hope it doesn't break anything else

[baldemar-wuda]

Same thing, way too low values.

[Freika]

@framesfree The issue with this PR is that it will cause the same problem for those who don't experience wrong speed calculation. Have a look at https://github.com/Freika/dawarich/releases/tag/0.24.0

[narucx]

Im on 0.28.1 and for me it shows the kms value in points and map
If i multiply the values with 3.6 I get to the correct kmh value

I have an even better example
I dont think that my plane flew with 170-220 km/h

Im using Owntracks as tracker

[23Suvu]

I have some extra information to add to the confusion. The following is a section of one of my tracks :
When looking at the data in the (My Data > Points) page, the speed values are too low (I was cycling at the time), but from what I've read, this is to be expected as I used OwnTracks which records in km/h, while Dawarich expects m/s. Edit : Ignore that, it appears that Dawarich is correctly converting from km/s to m/s when receiving data from the Owntracks endpoint. The issue here is that the data on the Points page is not being converted back to km/s as the table header would suggest.

However on the Map screen, things get interesting.
The speed values when hovering over a section of the route are roughly the same as shown in the points page.
But when clicking on one of the points the speed is now showing the correct converted speed (m/s > km/h).
https://github.com/user-attachments/assets/62a54ab8-2977-4b30-a638-f9d066728550

Apologies that my cursor was not captured in the video, I'm first hovering over each route section, followed by selecting each point.
The values are :

Route:      9      8      7      4      10     10
Points: 34     30     26     15     37     37     29

Dawarich 0.28.1
OwnTracks 2.5.3 (Android) for location recording

Side note : The points on the map show the time with the timezone offset applied, but not on the points page which only shows the offset in the tooltip. This can be a little confusing to match up data between the two views.

[Kiriyashiki]

I have the same behavior. Speed is correct on the tooltips, but wrong in the route tooltips and the points page

[leeaash]

I think the speed unit shows on points page should be m/s, not km/h

[Huskiefluff]

One thing i have noticed.
i use MP/H and if the site ever changes to KM/S in the settings for the user, it breaks all the milage calculations on everything, including speed, miles tracked, etc. It converts them to KM but never back, and just seems permanent.

[MarkJaroski]

I agree with @leeaash that m/s should be the base unit, since it makes conversion to all of the rest easier, and for some reason I'm able to use it across transport velocities, from walking to orbiting, whereas the usefulness of miles/hr and km/hr seem limited to driving.

[Freika]

Okay, Owntracks endpoint you're all using (/api/v1/owntracks) to create your points from GPSLogger expects speed in km/h, because Owntracks sends it that way. My understanding is, the issue comes from GPSLogger sends speed in meters per second, is that right?

[zittel05]

Hello Freika,
thanks for clarification but this seems surprising to me. If I understand correctly, GPS Logger can send speed data either as m/s (tag %SPD) or as km/h (%SPD_KPH)?
This is also part of the Docs: https://dawarich.app/docs/tutorials/track-your-location/#gps-logger
URL: http:///api/v1/owntracks/points?api_key=YOUR_API_KEY
HTTP Body:
{
"_type" : "location",
"t": "u",
"acc": "%ACC",
"alt": "%ALT",
"batt": "%BATT",
"bs": "%ISCHARGING",
"lat": "%LAT",
"lon": "%LON",
"tst": "%TIMESTAMP",
"vel": "%SPD"
}
and has also been discussed in https://github.com/Freika/dawarich/issues/700#issuecomment-2609095116.

Should I change in GPS Logger back to %SPD_KPH? Will that solve the issue?

Thanks.

[Freika]

@zittel05 if you could test if for me and see if the resulting values will be correct, I'll simply update docs.

Can you please check? Thanks

[zittel05]

Yes, I will start in 5 minutes for a short trip outside :-).