Paper Info
Title
Gnome: A Practical Approach to NLOS Mitigation for GPS Positioning in Smartphones.
Abstract
Accurate positioning in urban areas is important for personal navigation, geolocation apps, and ride-sharing. Smartphones localize themselves using GPS position estimates, and augment these with a variety of techniques including dead reckoning, map matching, and WiFi localization. However, GPS signals suffer significant impairment in urban canyons because of limited line-of-sight to satellites and signal reflections. In this paper, we focus on scalable and deployable techniques to reduce the impact of one specific impairment: reflected GPS signals from non-line-of-sight (NLOS) satellites. Specifically, we show how, using publicly available street-level imagery and off-the-shelf computer vision techniques, we can estimate the path inflation incurred by (the extra distance traveled by) a reflected signal from a satellite. Using these path inflation estimates we develop techniques to estimate the most likely actual position given a set of satellite readings at some position. Finally, we develop optimizations for fast position estimation on modern smartphones. Using extensive experiments in the downtown area of several large cities, we find that our techniques can reduce positioning error by up to 55% on average.
Year
DOI
Venue
2018
10.1145/3210240.3210343
MobiSys '18: The 16th Annual International Conference on Mobile Systems, Applications, and Services Munich Germany June, 2018
Keywords
Field
DocType
GPS,Localization,NLOS Mitigation,Mobile Computing
Mobile computing,Non-line-of-sight propagation,Satellite,Computer science,Geolocation,Real-time computing,Dead reckoning,Global Positioning System,GPS signals,Map matching
Conference
ISBN
Citations 
PageRank 
978-1-4503-5720-3
2
0.40
References 
Authors
19
3
Name
Order
Citations
PageRank
Xiaochen Liu1133.69
Suman Nath22907164.98
ramesh govindan3154302144.86