National Aerospace Laboratory Flight Division
National Aerospace Laboratory Flight Division
National Aerospace Laboratory Flight Division
National Aerospace Laboratory Flight Division
National Aerospace Laboratory Flight Division
Toshiba Corporation Komukai Works
Toshiba Corporation Komukai Works
The FANS (Future Air Navigation System) committee, under the ICAO (International Civil Aviation Organization), is studying utilization of the global navigation satellite system and advising on the development of a GPS (Global Positioning System) precision approach and landing navigation system for improving flight safety around terminal areas. The principal problems in the creation of the system are as follows: (1) achieving sub-meter level accuracy; (2) providing six-degree of freedom navigation information characterized by a wide dynamic range; and (3) creating a system with high availability and high continuity. The FAA (Federal Aviation Administration) of the United States, in cooperation with several universities and laboratories, is developing a DGPS (Differential GPS) navigation system for Category 3 landing, which provides high positioning accuracy using the smoothed pseudorange. Meanwhile a decision has been made to discontinue development of the kinematic GPS navigation system using the carrier phase because of problems with availability and continuity even if the system has centimeter-level positioning accuracy. A GPS navigation system using the carrier phase is proposed, based on an idea different from that of FAA's kinematic GPS navigation. The system employs the INS (Inertial Navigation System), widely recognized as a reliable form of navigation avionics, to provide six-degree of freedom navigation information, and achieve a wide dynamic range, high availability and high continuity. Navigation accuracy is improved by integrating the INS with the DGPS. For the DGPS/INS integration, the carrier phase as a measurement for filtering the INS drift error was used. The proposed system then performs sub-meter level navigation because the carrier phase is tolerant to multipath errors in comparison with the pseudorange. The proposed system was evaluated via flight experiments using the NAL Dornier 228, while error analysis ensured the observability of the carrier phase ambiguity and the improvement of positioning accuracy. The experimental results show sub-meter level accuracy and robustness to the cycles slips resulting in high availability and high continuity.
搬送波位相DGPS/INS複合航法による精密進入着陸航法システムの開発
naltr0001399.pdf
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