Location.getAccuracy() never reporting accuracy better than 3M when using FusedLocationProviderClient [118789585]

WAI

Bug

[AOSP] assigned

Status Update

No update yet.

Description

jd...@gmail.com

created issue #1

Nov 1, 2018 07:15PM

The `FusedLocationProviderClient` never reports an accuracy less than 3m?

Reproducible steps are provided in the Location samples on GitHub, see issue

https://github.com/googlesamples/android-play-location/issues/151.

I will explicitly add reproducible code here:

Update res/layout/main_activity.xml with the following:

<TextView
android:id="@+id/accuracy_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="@dimen/small_margin"
android:layout_marginStart="@dimen/small_margin"
android:textSize="@dimen/default_text_size" />

Update MainActivity.java with the following:
// add widget (new line 143)
private TextView mAccuracyTextView;

// add label (new line 148)
private String mAccuracyLabel;

// locate UI widget (new line 174)
mAccuracyTextView = (TextView) findViewById(R.id.accuracy_text);

// set label (new line 180)
mAccuracyLabel = "Accuracy";

// set value of the UI field (new line 409/410)
mAccuracyTextView.setText(String.format(Locale.ENGLISH, "%s: %f", mAccuracyLabel,
mCurrentLocation.getAccuracy()));

Run the updated app. Expected output is the accuracy in the app to match the accuracy reported by device.

Android Build: Tested on 3 devices with the following build numbers:
- OPM2.171019.029
- NRD90M.T710XXU2DRB1
- M4B302

Devices:
- Pixel 2 XL
- Samsung Galaxy Tab S2
- Nexus 5

Expected output
Accuracy in updated sample app should match device accuracy

Current Output
App never shows accuracy below 3M even when device is reporting sub 3M accuracy.

The issue is with the result of calling `mCurrentLocation.getAccuracy()` as the result of that API call is never less than 3M even when the accuracy from `LocationManager` is less than 3M. The current accuracy reported is a fix from

https://issuetracker.google.com/79189573 Location.getAccuracy() never reporting accuracy better than 3M when using FusedLocationProviderClient, but we consider this still a bug in that accuracy reported should not be limited to 3M.

Also add the following details:
- Devices: Nexus 5, Pixel 2 XL, Samsung Galaxy Tab S2
- Google Play Services client library version: 11+
- Google Play Services version on the device: 12.5.29,
- Android SDK Version: 6.0.1, 7.0, 8.1.0, 9.0
- Was this working correctly on a previous version of Google Play Services?
N/A

Comments

jd...@gmail.com <jd...@gmail.com> #2Nov 1, 2018 07:19PM

Meant to use Public Trackers > Google Maps Platform > Android2 as component, can it be moved if appropriate when reviewed?

ad...@google.com <ad...@google.com> #3Nov 2, 2018 10:06AM

Assigned to ad...@google.com.

We have passed this to the development team and will update this issue with more information as it becomes available.

jd...@gmail.com <jd...@gmail.com> #4Nov 2, 2018 05:44PM

Great news! Look forward to any/all updates as they become available.

ad...@google.com <ad...@google.com> #5Nov 12, 2018 12:22PM

Status: Won't Fix (Intended Behavior)

Thanks for keeping an eye on accuracy estimate - your catch of the (too high) 10 meter floor was especially helpful. Regarding the approximately 3 meter limit you are currently observing, this is by design. In our experience, when Location accuracy reports from a GPS chipset are less than 3 meters, these are more often confidently wrong, than they are helpfully indicative of better accuracy. We continue to monitor location accuracy from GPS (and fusion with other technologies) and you can expect further improvements to the accurate estimate over time.

jd...@gmail.com <jd...@gmail.com> #6Nov 12, 2018 06:12PM

Thanks for taking the time to confirm the design and explain the reasoning, we look forward to future improvements.

pa...@gmail.com <pa...@gmail.com> #7Nov 12, 2018 09:38PM

There could be some inconsistency with the recent Google IO talk:
How to get one-meter location-accuracy from Android devices (Google I/O '18)

https://www.youtube.com/watch?v=vywGgSrGODU

Its confusing because this 3m limit is about GPS, but Fused is a combination of GPS, network, sensors, etc, and it appears that ALL Fused locations have this 3m limit. This talk is referring largely to WiFi round trip time to get 1m accuracy, so one issue is that this limit will also effect these locations, and consequently use cases such as indoor navigation.

Another issue is that it appears Fused is doing something to improve on GPS accuracy. I routinely see accuracy on my Pixel 2 from Fused a meter or so more accurate than from the GPS provider. I assume this is from sensors or some other fusion. Then when GPS provider gets down to about 4m the Fused provider will hit 3m and then stop at that limit. Based on this older IO talk I believe it is expected that Fused can do better than GPS alone. Here is a link started at the appropriate point in the talk.

https://youtu.be/OEvycEMoLUg?t=1750

So I'm not sure this issue is really resolved. Fused is a bit of black box so I might be getting something wrong here. If thats the case, please let us know how this is working or what might have changed.

jd...@gmail.com <jd...@gmail.com> #8Mar 4, 2020 03:09PM

What about when accuracy reported < 3M from a bluetooth external gps device? Should the 3M limitation still exist? It seems as though it does as in debugging a location result I see the sub meter accuracy get changed to 3M limit.

su...@gmail.com <su...@gmail.com> #9Oct 15, 2020 07:41AM

Is this also why Chrome on Android "resets" accuracy to 3.9m? This is a HUGE problem for professional surveying solutions. We are using high precision GPS connected via Bluetooth, and using Mock Location software. We see that Chrome gets the correct accuracy (ie 0.02m), shows this for a second, and then immediately "resets" it to 3.9m, resulting in bad accuracy data.

[Deleted User] <[Deleted User]> #10Oct 10, 2022 12:15PM

Is there any updates on this issue? I'm seeing the same problem as the previous poster: while using an external GPS device which can get sub-meter accuracy and setting this as the mock location provider, I'm still only getting a 3.9m accuracy.