Location accuracy

Anton Tananaev3 years ago

What does "precision of 6600" mean?

Julien3 years ago

In the modern web app if I click the Icon of the device it shows several details, one of which is about GPS precision (a radius as you mention above). I previously mistake the number, it's 3325.
Just to add: Google map geolocate the device without positioning error.

buhao752 years ago

Hello Traccar Community!
I have been testing the location functionality of the Android app in the last days quite heavily. With my device (Nokia 7.2 with android 11) the location accuracy shows 0 all the time when I have high accuracy enabled. With medium and low accuracy I get accuracy values > 0. When I have high accuracy enabled and use the location function of an browser application at the same time when the traccar location service is running I get accuracy values > 0 in my browser application.

Now my question: Is anybody of you using the high accuracy mode and is retrieving accuracy values > 0? If yes it might be a specific problem with my device. If no how can I test that there is no bug in the traccar application? I already tried in the android emulator but did not find an option to enter the GPS accuracy there. Thanks for your answer and all the best, buhao75

Anton Tananaev2 years ago

Zero accuracy (means very high) usually means GPS location. Why do you think there's a problem?

buhao752 years ago

Thank you very much for your fast answer. I know that 0 means very high accuracy. I think that there might be a problem because the location functionality in the browser is running at the same time as the traccar service. The accuracy in the browser shows something around 5 meters but the traccar positions show accuracy 0 all the time. I filtered my traccar database and have found no single value with accuracy > 0 when accuracy precision is set to high.

Anton Tananaev2 years ago

I think we just always send zero for GPS, but I might be wrong.

buhao752 years ago

Could you please check in the code if zero is send all the time because I do not exactly know where to look for? If it is like that I suggest to change it so that the accuracy retrieved from the GPS is sent.

Anton Tananaev2 years ago

You can check the source code.

buhao752 years ago

I have checked the source code. You are right:
Position.kt

 accuracy = if (location.provider != null && location.provider != LocationManager.GPS_PROVIDER) location.accuracy.toDouble() else 0.0,

Why was it implemented like this? I would suggest to use:

 accuracy = if (location.provider != null) location.accuracy.toDouble() else 0.0,
Anton Tananaev2 years ago

I believe the reason is to be consistent with most hardware devices and also not overload map. We show accuracy circle when accuracy is not zero. Showing accuracy for all devices will clutter the map and impact performance. Is there a reason you need accuracy for GPS locations? They usually have pretty standard accuracy around 30 meters.

buhao752 years ago

In my opinion it would be useful to have location accuracy also for GPS locations. For example you can snap to the right street if the distance from the location to the polyline is less than the location accuracy.

cosmic2 years ago

What does passive location accuracy actually means?

Anton Tananaev2 years ago

It means the app only receives location when some other app uses it.

cosmic2 years ago

please can you be more specific on this? some other app uses what?

Anton Tananaev2 years ago

Location.