Abstract: On the basis of analyzing the fundamental theory and structure of Federal Kalman Filtering (FKF), and in the need of Inertial Navigation System/Global Positioning System/Tarrain Aided Navigation(INS/GPS/TAN) integration, an FKF method when the dimensions of subsystem vectors are different, and a local FKF filter structure are provided. With the utilization of many new information fusion techniques such as Local State Expansion, Local State Truncation, Intelligent Filtering In Irregular Cycle, Multi Level Fault Detection and Gating, the reliability and adaptability are apparently improved with a satisfying precision.

Key words: information fusion, feder al Kalma n filtering, integr ated navigat ion, INS/ GPS/TAN