There are confusing, competing claims about location accuracy in the market. This panel will help the audience understand when more precise location is needed and when it isn’t and how to evaluate all the claims.

1. © Google 2016
Location Accuracy
Frank van Diggelen
Google
Place Conference, Chicago
21 September 2016

2. © Google 2016
Why is there a problem at all?
GPS signals attenuate at ~10 dB per wall,
after 3 walls, they’re practically invisible
GPS location is based on time-of-flight
2

3. © Google 2016
Worldwide test of accuracy
experienced by consumers
3
How accurate is GPS for consumers?
Source:
“The World's First GPS MOOC and Worldwide Laboratory using Smartphones”, van Diggelen, Stanford PNT Symposium 2016

4. © Google 2016
Source:
“The World's First GPS MOOC and Worldwide Laboratory using Smartphones”, van Diggelen, Stanford PNT Symposium 2016
Open sky, consumer accuracy = 5m
4
GPS MOOC experiments, over 1000 participants in over 100 countries.

5. © Google 2016 5
Plot of accuracy results vs Building height
Source:
“The World's First GPS MOOC and Worldwide Laboratory using Smartphones”, van Diggelen, Stanford PNT Symposium 2016

6. © Google 2016
What can we do about Urban Canyon?
Driving: Merge GPS with Motion Sensors.
6
Driving Walking or
First Fix
Fused Location
Network Location

7. © Google 2016
Other technologies
7
WiFi RSSI
Accel, Mag, Gyro, Baro
UltraSound
LEDs
PDR
Machine Learning
WiFi RTT
Vision
BLE
RFID
Cell ID
Metro Beacons

8. GetCurrentPlace
1
2
3
0.45
0.25
0.10
Output Predictions
Morocco’s
Restaurant
Machine Learning