Smartphone-based 3D in-building localization and navigation service

In this paper, we present a 3D indoor navigation service system based on smartphones. To achieve an accurate indoor navigation system in a multi-storey building, it is necessary to determine the storey where the user is. By attaching an atmosphere pressure sensor on smartphones, the altitude information of the user can be obtained, and then, the storey where the user is can be calculated indirectly. With the information of storey, we project localization anchor nodes, e.g. WiFi-AP, of different storeys onto the storey where the user is, and calculate their projection distances based on received signal strength (RSS). To utilize the projection distance in 2D localization algorithms, the systematic error deviation from the storey deviation can be reduced. In addition, we develop a software running in a smartphone to implement our localization method, and provide a smartphone navigation service in our office building. Experimental results show that our method is more accurate than the traditional triangle localization method.