Long baseline navigation with clock offset estimation and discrete-time measurements

• One-way-travel-time long baseline navigation solution with explicit estimation of a constant clock offset.
• Constructive observability analysis, leading to the design of a Kalman filter with globally exponentially stable error dynamics.
• Evaluation of the proposed solution, including Monte Carlo runs and the comparison with the extended Kalman filter.
• Tracking of slowly time-varying clock offset via appropriate tuning of the Kalman filter.

This paper proposes a novel one-way-travel-time long baseline filtering system that includes the estimation of the clocks’ offset, which is assumed constant. Considering discrete-time pseudo-range measurements, in addition to the data provided by a Doppler velocity log and an attitude and heading reference system, 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 to evaluate the proposed solution, which is also compared with the EKF, including Monte Carlo runs.