DeepGPS: Deep Learning Enhanced GPS Positioning in Urban Canyons.

Global Positioning System (GPS) has benefited many novel applications, e.g., navigation, ride-sharing, and location-based services, in our daily life. Although GPS works well in most places, its performance in urban canyons is well-known poor, due to the signal reflections of non-line-of-sight (NLOS) satellites. Tremendous efforts have been made to mitigate the impacts of NLOS signals, while previous works heavily rely on precise proprietary 3D city models or other third-party resources, which are not easily accessible. In this paper, we present DeepGPS , a deep learning enhanced GPS positioning system that can correct GPS estimations by only considering some simple contextual information. DeepGPS fuses environmental factors, including building heights and road distribution around GPS's initial position, and satellite statuses to describe the positioning context, and exploits an encoder-decoder network model to implicitly learn the complex relationships between positioning contexts and GPS estimations from massive labeled GPS samples. As a result, the well-trained model can accurately predict the correct position for each erroneous GPS estimation given its positioning context. We further improve the model with a novel constraint mask to filter out invalid candidate locations, and enable continuous localization with a simple mobility model. A prototype system is implemented and experimentally evaluated using a large-scale bus trajectory dataset and real-field GPS measurements. Experimental results demonstrate that DeepGPS significantly enhances GPS performance in urban canyons, e.g., on average effectively correcting 90.1% GPS estimations with accuracy improvement by 64.6%.