Satellite Navigation Integrity Risk Assessment

The patent segments the integrity risk calculation into multiple independent scenarios: one where all satellites are assumed error-free and another where each satellite is individually assumed to be faulty. This segmentation allows the system to evaluate different failure modes separately and combine results, improving both the accuracy of integrity assessment and the availability of position solutions by identifying which scenarios actually pose risks.

The patent applies partial action by calculating integrity risk only for relevant scenarios rather than exhaustively analyzing all possible satellite failure combinations. By focusing on the most critical cases (all satellites error-free vs. one satellite faulty) and using selective evaluation, the system achieves sufficient integrity assessment without the computational burden of complete analysis, thereby maintaining high availability.

The patent implements feedback mechanisms by continuously monitoring satellite signal quality and using this information to dynamically adjust integrity risk assessments. The system compares actual signal characteristics against expected values and uses this feedback to determine whether integrity alarms should be triggered, reducing false alarms while maintaining safety through adaptive threshold adjustment based on real-time conditions.

The patent changes the parameter of alarm threshold from a fixed value to a dynamically adjusted value based on calculated integrity risk. By modifying the alarm threshold parameter according to the assessed integrity risk level and scenario-specific conditions, the system optimizes the balance between safety and false alarm reduction, allowing stricter thresholds when risks are high and more lenient thresholds when risks are low.