Hybrid Integrity for Precision Guidance and Landing

The objective of this proposal is to develop a methodology for the improved integrity and continuity of absolute and relative GPS/IMU systems based on the architecture of the fault-tolerant estimator. This scheme is based on new results in analyticredundancy management methodologies. This methodology combines new robust fault detection filters with residual processor and fault magnitude reconstruction to develop fault-tolerant estimators, which operate at high level of integrity with lower levelintegrity hardware components. This system is applicable to all levels of coupling between the GPS receiver and the IMU, but is most critical for ultra-tight coupling of GPS/IMU since the replica signals generated from the INS is fed back to the receivercorrelators. The fault-tolerant estimator is proposed to ensure that the replica signals are to a very high probability not corrupted by GPS and IMU faults. This work can be applied anywhere where GPS/INS navigation is used as an enhancement to safety andintegrity of operations. Specifically, this work may be applied to autonomous carrier landing, autonomous aerial refueling, formation flight for drag reduction, and relative navigation for munitions guidance.