The development of indoor navigation services and algorithms is becoming a popular trend in the IT industry in recent years. Some of the modern buildings, like airports, shopping malls, and warehouses have grown enough (Fig.1) to feel a need for their own navigation tools for customers. Closed environment conditions exclude the usage of common satellite-based navigation systems like GPS or GLONASS, so nowadays some alternative information sources of user localization appear at the scene. Fig.1.
