  This paper addresses the problem of simultaneous estimation of the position,
linear velocity and orientation of a rigid body using single bearing
measurements. We introduce a Riccati observer-based estimator that fuses
measurements from a 3-axis accelerometer, a 3-axis gyroscope, a single
body-frame vector observation (e.g., magnetometer), and a single
bearing-to-landmark measurement to obtain the full vehicle's state (position,
velocity, orientation). The proposed observer guarantees global exponential
convergence under some persistency of excitation (PE) condition on the
vehicle's motion. Simulation results are presented to show the effectiveness of
the proposed approach.
