Using a Map of Measurement Noise to Improve UWB Indoor Position Tracking

Ultrawideband signals present new opportunities for indoor position tracking due to their ability to operate in non-line-of-sight conditions. However, walls and other normal indoor infrastructure cause a systemic spatial warp in the measurements. In this paper, we describe methods to manually build a map of the measurement noise and use it in a particle filter framework to improve measurement accuracy. We tested our methods in two facilities, collecting over 5.6 million measurements. Evidence shows that the measurement noise is multimodal, location dependent, stable over time, and locally similar. Using the map in a particle filter framework, we demonstrate an average improvement in measurement accuracy of 30%.