A pocket guide to indoor mapping

In this paper, we present a way to obtain accurate WLAN signal strength maps in indoor environments, without dedicated hardware, and without a time consuming and complicated training process. We need two contributions towards this end. First, we present a novel dead-reckoning technique, to gather accurate user motion estimates. This motion data is combined with information about the signal strength of access points of the wireless infrastructure. Our second contribution lies in the efficient integration of this complementary information into a system that allows for easy mapping and requires nothing but a smartphone. All the required data is gathered from people walking casually around in an area of interest while carrying a smartphone in their pocket.