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I'm trying to find a way to improve the accuracy obtained from Google Play Services's Fused Location Provider.

I'm testing an app that uses LocationServices and allows the user to choose from a set of update frequencies (every 30 seconds, every min, every 5 min, every 10 min). It then requests location updates from the fused location provider with the chosen interval, with a priority of PRIORITY_HIGH_ACCURACY.

It works, but the locations obtained don't seem to be as accurate as they could be. The accuracy values are typically more than 10 meters, while a third party GPS app (such as GPS test) typically reaches better accuracy if I wait long enough.

The Android documentation has the following to say:

The priority of PRIORITY_HIGH_ACCURACY, combined with the ACCESS_FINE_LOCATION permission setting that you've defined in the app manifest, and a fast update interval of 5000 milliseconds (5 seconds), causes the fused location provider to return location updates that are accurate to within a few feet. This approach is appropriate for mapping apps that display the location in real time.

Indeed, when I choose a very small frequency (such as 5 seconds or 2 seconds), I notice an overall improvement in the accuracy of the obtained locations - they sometimes get as good as 3-4 meters. However, it looks like choosing larger update intervals result in lower accuracy.

So I'm thinking of the following strategy: schedule a task that, at the interval chosen by the user: (1) starts requesting location updates every few seconds (2 seconds), (2) waits for 20 seconds, then (3) stop requesting updates.

I tried to use a Handler in foreground service to accomplish that. It works when the screen is on, but, as soon as the screen is turned off, the scheduling becomes seemingly unpredictable. So it looks like I'll have to resort to something like AlarmManager to schedule this task. This answer suggests a similar approach: https://stackoverflow.com/a/26298509/1131904 ; I also found this article, which tackles the similar problem of how to schedule periodic tasks in a battery efficient way: https://wangjingke.com/2016/09/23/Multiple-ways-to-schedule-repeated-tasks-in-android

Has anyone else run into a similar problem? Is using AlarmManager a good approach?

favq
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1 Answers1

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To answer you first question, we have made the some observation. In general, the occurrence of high-accuracy locations (3-10 m) decreases with increasing interval. However, the exact behavior seems to differ between vendors. On Samsung S9 and S8, the threshold appeared to be at 10 seconds. Above this interval, high-accuracy locations were very rare. On other devices (Pixel 3a, Xiaomi MI 8, OnePlus 6T) high-accuracy locations were still frequent at an interval of 30 seconds. All observations were made under open sky.

Henrik Koberg
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