GES Long Baseline Navigation with clock offset estimation

Long Baseline (LBL) acoustic positioning systems usually operate using either round-trip techniques or synchronous clocks. In practice, it is an additional burden to synchronize the clocks of the external transponders and that of the agent. This paper proposes a novel filtering solution that includes the estimation of the offset of the clocks, in addition to the position and velocity of the agent. Based on discrete-time pseudo-range measurements, an augmented system is derived that can be regarded as linear for observability and observer design purposes. Its observability is discussed and a Kalman filter provides the estimation solution, with globally exponentially stable (GES) error dynamics. Simulation results are presented, considering noisy measurements, to evaluate the proposed solution, which evidence good performance.