Open Radar

 
Area:
CoreLocation (Location Services)

Summary:
CoreLocation on watchOS will return poor points (1414m h_acc or similar) with non-changing latitude/longitude that haven’t previously occurred in the position stream but are close to previous points and are far from the current position. This bad stream of locations seems to be correlated to when the user stops moving. We have no issues with these bad locations when the user turns off wifi/Bluetooth on their phone to ensure they’re unconnected from watchOS.

```
│INDEX   │ TIME                 │ Δ TIME   │ LAT, LNG                 │ H_ACC       │ SPEED       │DISTANCE      │ Δ DIST
│ 1866    │ 2016-12-07T04:26:42Z │ 0.94s    │ [37.773812, -122.467177] │ 12.241834m  │ 0.009693m/s │ 57192.151154m │ 0.0980039999995m
│ 1867    │ 2016-12-07T04:26:44Z │ 2.17s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 562.826703m
│ 1868    │ 2016-12-07T04:26:45Z │ 1.52s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1869    │ 2016-12-07T04:26:46Z │ 0.09s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1870    │ 2016-12-07T04:26:46Z │ 0.03s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1871    │ 2016-12-07T04:26:46Z │ 0.11s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1872    │ 2016-12-07T04:26:46Z │ 0.33s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1873    │ 2016-12-07T04:26:46Z │ 0.00s    │ [37.777181, -122.462402] │ 1414m       │ -1m/s       │ 57754.977857m │ 0.0m
│ 1874    │ 2016-12-07T04:26:52Z │ 5.95s    │ [37.773775, -122.466918] │ 48m         │ 1.532089m/s │ 58303.777334m │ 548.799477m
│ 1875    │ 2016-12-07T04:26:53Z │ 1.22s    │ [37.773865, -122.467045] │ 32m         │ 1.532089m/s │ 58318.791781m │ 15.014447m
```

Observations:
1. Location that repeats hasn’t previously occurred in stream
2. Location that repeats tends to be close to previous points at some previous time
3. Jump back to point occurs at multiple times throughout a bike ride
4. Point that is jumped to can change throughout a bike ride
5. Doesn’t reproduce on watchOS when disconnected from the phone
6. Seems correlated to when we stop moving

Steps to Reproduce:
1. Start CoreLocation location updates on watchOS application with phone connected.
2. Ride bike along the road for a bit and eventually stop (at something like a stop light).

Expected Results:
The users’ location is reported as being at the location they stopped or close by.

Actual Results:
The users’ location is reported somewhere near their previous path but a non-duplicated point.

Version:
Multiple Apple Watch Series 0 & Series 2 devices with watchOS 3.1 (14S471).

Notes:
This makes a bike commute from our office (SOMA) to home (which is approximately 5 miles) end up being 50+ miles because this occurs multiple times throughout the ride. We are leaning toward thinking it's when the system (CoreLocation) switches from one source to another (phone to watch or vice versa) because of the non-moving locations.

Configuration:
`CLLocationManager` with `kCLLocationAccuracyBest` and `kCLDistanceFilterNone`.