Observability analysis of the time-varying dynamics yields geometric insights about the unobservable subspace.

Camera and IMU jointly rotating in distinct piece-wise constant attitude segments during a straight path yield observable IMU errors.

The analysis shows the effect of lateral maneuvers on the observability of misalignment, and velocity error along and orthogonal to the ground velocity.

Monte Carlo simulation indicates the fusion of inertial and optical flow data mitigates the position error growth relative to just unaided inertial navigation during GPS outage.