Traccar client sends fantasy data points

Artiom3 years ago

I'm frequently getting this kind of data sequences from the client, especially when phone is not moving:

2021-02-03 00:36:46	-33.847051	151.215002	34 m	2.3 kn
2021-02-03 00:37:19	-33.847570	151.228460	6219 m	1.0 kn
2021-02-03 00:37:53	-33.857921	151.217610	3021 m	0.0 kn
2021-02-03 00:38:32	-33.847248	151.215075	107 m	0.1 kn
2021-02-03 00:39:00	-33.847164	151.214920	71 m	0.4 kn

Look at the elevation, and point itself is "jumping" around for several kilometres. It's most probably GPS "feature", but is it possible to filter out these kind of points?

Anton Tananaev3 years ago

There is no filtering by elevation, but maybe you can filter by some other parameters.

Artiom3 years ago

Ok, I've tried to setup distance filter based on documentation:

coordinates.filter config

Replaces coordinates with last known if change is less than a "coordinates.error" meters. Helps to avoid coordinates jumps during parking period.
coordinates.minError config

Distance in meters. Distances below this value gets handled like explained in "coordinates.filter".
coordinates.maxError config

Distance in meters. Distances above this value gets handled like explained in "coordinates.filter", but only if Position is also marked as "invalid".

So I've added those 2 lines:

<entry key='coordinates.filter'>true</entry>
<entry key='coordinates.maxError'>1000</entry>

Still I can see points like this:

batteryLevel=74.0  distance=1357.47  totalDistance=464182.5  motion=true
batteryLevel=74.0  distance=1319.84  totalDistance=465502.34  motion=true

all marked valid.

Artiom3 years ago

Is it possible to define filter's maxs and mins at the device level?
I had some success with configuring it however it may be not useful to have them for all devices

Anton Tananaev3 years ago

Not possible currently.

Mark3 years ago

Hi Anton, just wondered why the filtering coordinates.maxError is only applied when the position is flagged as 'invalid'? I have the traccar client on medium accuracy and 30 minute updates (when not moving), and during the night I always get a few outliers up to 1km (which flags an exit of geofence event) that I cannot seem to filter out. Looking at the route the speed logged with this fix is 0 knots., so I cannot filter out on maximum speed either...

On the web page there is a grey circle around each device. Is this supposed to be SMA/error ellipse? Can we not set a filter on SMA to reject position if error ellipse is greater than N at 95% probability?

Cheers,

Mark