This paper investigates the integration of vision-based measurements into civil aircraft navigation systems to enhance continuity and robustness during precision approach operations.

It proposes a tightly coupled hybrid architecture combining inertial sensors, SBAS-augmented GNSS, barometric data, and landmark-based vision measurements, with data fusion performed via an error-state Kalman filter.

The study formally analyzes the impact of vision integration on continuity and integrity performance, highlighting the introduction of new failure modes and the resulting constraints on system-level risk allocation.

To address these challenges, a dual-navigation architecture is proposed, separating GNSS-based and vision-based navigation solutions and enabling seamless switching in case of GNSS unavailability. This approach preserves established GNSS integrity requirements while leveraging vision to maintain operational continuity in degraded or interference-prone environments.