In integrated navigation, an integrity breach scenario refers to a fault or anomaly in sensor data. Which techniques are used to detect such breaches?

• A. Manual inspection of sensor readings
• B. Exclusion or reconfiguration of sensors
• C. Residual analysis, consistency checks, and integrity monitors like RAIM/FDE
• D. Random checks of data consistency

Answer: (C)

In integrated navigation, detecting an integrity breach means using automatic, quantitative checks that reveal when sensor data behave inconsistently with the navigation solution. The most effective approach combines residual analysis, consistency checks, and dedicated integrity monitors such as RAIM and FDE.

Residual analysis looks at the difference between what the sensor measurements say and what the navigation model predicts. If those residuals are larger than expected, it signals a fault in a sensor or measurement. Consistency checks compare information from multiple sensors or estimation paths to see if they agree within defined tolerances; disagreement suggests some data are unreliable. Integrity monitors like RAIM (Receiver Autonomous Integrity Monitoring) exploit measurement redundancy to test the overall health of the solution and identify suspicious data. Fault Detection and Exclusion (FDE) goes a step further by not only detecting a fault but also isolating and excluding the faulty measurement from the computation, preserving the integrity of the navigation solution.

Manual inspection and ad hoc checks aren’t timely or reliable enough to catch faults as they happen, and simply excluding or reconfiguring sensors is a response once a problem is detected rather than a primary detection method.