Measuring And Monitoring Method And Error Analysis Of The Installed Matrix About Star Sensors And Magnetometers

Geomagnetic navigation as a new kind of navigation system, for its advantages of autonomous, all-weather, no error accumulation, high precision and wide applicable range, is widely used in aerospace, aviation, ocean navigation and other fields. Using advanced technology for precision measurement of the geomagnetic filed to improve the precision of magnetic survey, and establish the database of the precision geomagnetic field, has become one of hot topics in geomagnetic navigation field. Satellite geomagnetic measurement is an import tool of the global geomagnetic surveying and mapping, which can be global, all-weather and high precision to measure geomagnetic field and obtain high quality and high precision of geomagnetic field all the ground. Because the calibration precision of the installed matrix of star sensors and magnetometers is the key technology for determing the geomagnetic measurement precision of satellite geomagnetic measurement system, and how to improve the calibration precision of the installed matrix has important research significance, the paper develops the study of the measuring and monitoring methods of the installed matrix of star sensors and magnetometers.Firstly, the composition of satellite geomagnetic measurement system, the necessity of the installed matrix calibration, including grounding calibration and on-orbit monitoring are discussed. Concerned coordinate systems are given, and the expresion of magnetometer measurement data in geographic coordinate system is deduced. The overall design schemes of the outdoor calibration and indoor turntable calibration are given, the overall design schemes of autocollimator-reflector and gratings angular on-orbit monitoring is also given, and the feasibility and precision analysis of the scheme are demonstrated. Above research lays the foundation for the installed matrix calibration.Secondly, the outdoor test scheme of the installed matrix of star sensors and magnetometers is designed with the known geomagnetic field intensity, stars vector and local latitude and longitude. Simulation algorithm based on Monte Carlo method is designed to identify the error parameter, the identification precision of the error parameters and the each angle measurement precision of the installed matrix of star sensor and magnetometer are analyzed. Simulation shows that the measurement precision of each angle of the installed matrix of star sensor and magnetometer is low, and can’t meet the design requirement for the system.Thirdly, the indoor test scheme of the installed matrix of star sensors and magnetometers is designed with high-precision non-magnetic turntable, standard magnetic field, star simulator, theodolite and other measurement equipment, and the practical expression of the installed matrix is given. Simulation algorithm is designed to verify distribution characteristics if error parameters, and the identification precision of the error parameters and the measurement precision of each angle of the installed matrix of star sensor and magnetometer are analyzed. Simulation shows that the calibration precision of indoor turntable is a little high, and the calibration precision of each angle of the installed matrix is better than 5", can meet the requirement for system specifications.Finally, a set of autocollimator-reflector monitoring system is designed with optical autocollimation principle, and its calibration is carried out with high-precision dividing head, measurement precision satisfies the requirement of specifications. Ground functional monitoring experiment is designed to verify the feasibility of the autocollimator-reflector monitoring method, the measurement precision also meets the requirement of specifications. A set of gratings monitoring system is designed with the gratings moire fringes angle measuring principle, and its uncertainty of measurement is analyzed, the precision meets the requirement of sepcifications. The feasibility of gratings monitoring method is verified with ground functional monitoring experiment, and the measurement precision also meet the requirement of the specifications.