The integrity requirement should be satisfied when GNSS is used in aviation.There are now two ways for integrity monitoring,that is,receiver autonomous integrity monitoring(RAIM) and GNSS integrity channel(GIC) based ...The integrity requirement should be satisfied when GNSS is used in aviation.There are now two ways for integrity monitoring,that is,receiver autonomous integrity monitoring(RAIM) and GNSS integrity channel(GIC) based on augmentation system.The rapid development of the Beidou satellite navigation system(COMPASS) will significantly improve the satellite geometry.Besides,the effects of first order ionosphere delay will be mitigated by the combination of GNSS multi-frequency signals.The availability of RAIM will be enhanced,which makes it possible to provide a worldwide seamless integrity service for aviation by using RAIM.The contribution of COMPASS to the availability of RAIM is analyzed by simulation;and the integrity requirement of which aviation approaching phrase can be satisfied when using COMPASS single system and its combination with other satellite navigation system is analyzed.Moreover,the influence of user range accuracy(URA) of COMPASS on integrity performance is discussed.展开更多
Image matching technology is theoretically significant and practically promising in the field of autonomous navigation.Addressing shortcomings of existing image matching navigation technologies,the concept of high-dim...Image matching technology is theoretically significant and practically promising in the field of autonomous navigation.Addressing shortcomings of existing image matching navigation technologies,the concept of high-dimensional combined feature is presented based on sequence image matching navigation.To balance between the distribution of high-dimensional combined features and the shortcomings of the only use of geometric relations,we propose a method based on Delaunay triangulation to improve the feature,and add the regional characteristics of the features together with their geometric characteristics.Finally,k-nearest neighbor(KNN)algorithm is adopted to optimize searching process.Simulation results show that the matching can be realized at the rotation angle of-8°to 8°and the scale factor of 0.9 to 1.1,and when the image size is 160 pixel×160 pixel,the matching time is less than 0.5 s.Therefore,the proposed algorithm can substantially reduce computational complexity,improve the matching speed,and exhibit robustness to the rotation and scale changes.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant Nos.41020144004 and 41104022)the National High-tech R&D Program of China(Grant No.2013AA122501)
文摘The integrity requirement should be satisfied when GNSS is used in aviation.There are now two ways for integrity monitoring,that is,receiver autonomous integrity monitoring(RAIM) and GNSS integrity channel(GIC) based on augmentation system.The rapid development of the Beidou satellite navigation system(COMPASS) will significantly improve the satellite geometry.Besides,the effects of first order ionosphere delay will be mitigated by the combination of GNSS multi-frequency signals.The availability of RAIM will be enhanced,which makes it possible to provide a worldwide seamless integrity service for aviation by using RAIM.The contribution of COMPASS to the availability of RAIM is analyzed by simulation;and the integrity requirement of which aviation approaching phrase can be satisfied when using COMPASS single system and its combination with other satellite navigation system is analyzed.Moreover,the influence of user range accuracy(URA) of COMPASS on integrity performance is discussed.
基金supported by the National Natural Science Foundations of China(Nos.51205193,51475221)
文摘Image matching technology is theoretically significant and practically promising in the field of autonomous navigation.Addressing shortcomings of existing image matching navigation technologies,the concept of high-dimensional combined feature is presented based on sequence image matching navigation.To balance between the distribution of high-dimensional combined features and the shortcomings of the only use of geometric relations,we propose a method based on Delaunay triangulation to improve the feature,and add the regional characteristics of the features together with their geometric characteristics.Finally,k-nearest neighbor(KNN)algorithm is adopted to optimize searching process.Simulation results show that the matching can be realized at the rotation angle of-8°to 8°and the scale factor of 0.9 to 1.1,and when the image size is 160 pixel×160 pixel,the matching time is less than 0.5 s.Therefore,the proposed algorithm can substantially reduce computational complexity,improve the matching speed,and exhibit robustness to the rotation and scale changes.
