Federated Kalman filter for rate azimuth inertial platform/log/gravity matching integrated navigation system

Rate azimuth inertial platform/log/gravity matching is a simple passive navigation system, to improve its fault-tolerant performance, and a federated Kalman filter is designed for this integrated system. The fundamental structure is constituted, and the algorithm is presented. The federated kalman filter makes full use of the log providing speed information, and adapts non-interval filter to fuse information. The simulation of the integrated navigation system is carried out with Matlab/Simulink and gravity anomaly maps whose resolution is 0.005°×0.005°. The theoretical analysis and the experimental results show that using this federated kalman filter, the fault tolerance capability can be enhanced, and the positioning accuracy is the same as that using the centralized kalman filter.