Applying the technique of computer tomography to ionosphere detection,Computerized Ionospheric Tomography(CIT) can produce the large scale distribution of electron density in a two dirnentional longitudinal section o...Applying the technique of computer tomography to ionosphere detection,Computerized Ionospheric Tomography(CIT) can produce the large scale distribution of electron density in a two dirnentional longitudinal section of ionosphere. According to the actual detecting condition of sparse receiver and limited projecting angle,polynomial interpolation method and projecting angle expansion method are proposed. A new energy function is formulated according to the constraint of least neighbourhood error. Simulated annealing is incorporated in the iteration of ART to get the global minimum of energy function.展开更多
Using the empirical ionospheric model, the flux-tube integrated electron density and the ratio between the F-region Pedersen conductivity and the total E- and F-region Pedersen conductivity are calculated to investiga...Using the empirical ionospheric model, the flux-tube integrated electron density and the ratio between the F-region Pedersen conductivity and the total E- and F-region Pedersen conductivity are calculated to investigate the characteristics of the ionospheric asymmetry after sunset during a solar cycle. Furthermore, two indices representing the asymmetric strength of the parameters respectively are defined to study its relationship with the occurrences of the irregularities during different seasons and with different solar activities. The results indicate that the electron density and the Pedersen conductivity ratio show north-south remarkable hemispheric asymmetry at different solar energy levels. The asymmetric strengths represent the dependence on seasons and solar activities, and their variation depending on seasons and solar activities show a negative correlation with the occurrences of the equatorial irregularities and also have a negative relation with the linear growth rate of the generalized Rayleigh-Taylor instability.展开更多
文摘Applying the technique of computer tomography to ionosphere detection,Computerized Ionospheric Tomography(CIT) can produce the large scale distribution of electron density in a two dirnentional longitudinal section of ionosphere. According to the actual detecting condition of sparse receiver and limited projecting angle,polynomial interpolation method and projecting angle expansion method are proposed. A new energy function is formulated according to the constraint of least neighbourhood error. Simulated annealing is incorporated in the iteration of ART to get the global minimum of energy function.
基金Supported by the National Natural Science Foundation of China(41474134,41474135,41127003)the Hubei Key Laboratory of Intelligent Wireless Communications
文摘Using the empirical ionospheric model, the flux-tube integrated electron density and the ratio between the F-region Pedersen conductivity and the total E- and F-region Pedersen conductivity are calculated to investigate the characteristics of the ionospheric asymmetry after sunset during a solar cycle. Furthermore, two indices representing the asymmetric strength of the parameters respectively are defined to study its relationship with the occurrences of the irregularities during different seasons and with different solar activities. The results indicate that the electron density and the Pedersen conductivity ratio show north-south remarkable hemispheric asymmetry at different solar energy levels. The asymmetric strengths represent the dependence on seasons and solar activities, and their variation depending on seasons and solar activities show a negative correlation with the occurrences of the equatorial irregularities and also have a negative relation with the linear growth rate of the generalized Rayleigh-Taylor instability.
