Tightly Coupled Passive UWB Localization for Low-Density Anchor Networks

This study investigates the effectiveness of a passive tightly coupled ultra-wideband (UWB) based inertial navigation system for indoor positioning of mobile platforms. Unlike conventional methods that rely on time difference of arrival (TDOA) or two-way ranging (TWR) measurements, the proposed approach utilizes local reception timestamps directly. An error state Kalman filter with right quaternion error definition is used in the state estimation process. Evaluation is performed first in a Matlab simulation environment and then, using a dataset acquired by flying a quadcopter while moni- tored by a motion capture system. Timestamp measurements were acquired using custom firmware flashed onto Decawave DWM 1000-DEV hardware. Our findings demonstrate that the proposed system outperforms traditional TDOA methods, providing accurate measurements even in the presence of communication interruptions, with as few as one anchor.