The integration of Geostationary Earth Orbit(GEO)satellite constellations into Sixth Generation(6G)framework for cellular networks is essential to achieve global connectivity.Despite the major importance of this integ...The integration of Geostationary Earth Orbit(GEO)satellite constellations into Sixth Generation(6G)framework for cellular networks is essential to achieve global connectivity.Despite the major importance of this integration,current research often underestimates the limitations imposed by available satellite payload power,erroneously assuming a uniform maximum power density distribution across all communication beams.In this paper,we propose an Efficient Downlink Resource Allocation scheme(EDRA)that accounts for transmitting power resource limitations,variable service quality demands,and a heterogeneous number of users.Our approach relies on the thorough analysis of real-world demographic data,allowing us to optimize the allocation of downlink power and time-frequency resources in a practical and effective manner.Furthermore,we introduce an optimization model to maximize the total system revenue,using an iterative algorithm specifically designed to solve complex optimization problems.Numerical simulations demonstrated that the EDRA scheme improved the average network revenue by more than 66%relatively to standard methods,with performance gains increasingly large for an increasing diversity of service types,establishing the robustness and adaptability of the proposed EDRA scheme in the rapidly-evolving context of satellite-based communication systems.展开更多
With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on pre...With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.展开更多
This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in t...This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.展开更多
The sensible and latent heat fluxes over the ocean area near China were calculated and analyzed by usingthe Goddard Earth Observing System (GEOS) - four-dimensional Data Assimilation System (DAS). The calculated resul...The sensible and latent heat fluxes over the ocean area near China were calculated and analyzed by usingthe Goddard Earth Observing System (GEOS) - four-dimensional Data Assimilation System (DAS). The calculated results showed that the sensible heat flux had its large value in winter and autumn , small value in spring and summer overthe ocean area near China. In winter, the sensible heat flux increased distinctly with latitude, and its isolines were verycrowded. Over the ocean area east of Taiwan Province and south of Japan, the direction of isoline was from southwestto northeast. In the South China Sea the sensible heat flux was lower than that of surrounding ocean areas,and its isoline was distributed into a type of an inverted trough. In autumn and winter, the maximum center of latent heat flux appeared over the ocean area northeast of Taiwan Province and south and southeast of Japan, meanwhile, the isoline wasin the direction of southwest to northeast. In spring and summer, the latent heat flux had minimum value in the Huanghai Sea. At the same time, the maximum value center of latent heat flux appeared over the ocean area south of Japan inspring.展开更多
Scheme of positioning constellation would greatly influence the positioning performance. In this paper, a GEO/HEO hybrid constellation with 3 HEO satellites deployed in 3 orbits and 3 GEO satellites for regional posit...Scheme of positioning constellation would greatly influence the positioning performance. In this paper, a GEO/HEO hybrid constellation with 3 HEO satellites deployed in 3 orbits and 3 GEO satellites for regional positioning is presented. Firstly, elements for 3 GEO and 3 HEO are optimized from regional visibility for the selected region of interest. Secondly, positioning performance is provided through GDOP(geometric dilution of precision) and PDOP(positional dilution of precision). Simulation results show that similar accuracy with GPS can be gained by this constellation.展开更多
基金supported by Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)。
文摘The integration of Geostationary Earth Orbit(GEO)satellite constellations into Sixth Generation(6G)framework for cellular networks is essential to achieve global connectivity.Despite the major importance of this integration,current research often underestimates the limitations imposed by available satellite payload power,erroneously assuming a uniform maximum power density distribution across all communication beams.In this paper,we propose an Efficient Downlink Resource Allocation scheme(EDRA)that accounts for transmitting power resource limitations,variable service quality demands,and a heterogeneous number of users.Our approach relies on the thorough analysis of real-world demographic data,allowing us to optimize the allocation of downlink power and time-frequency resources in a practical and effective manner.Furthermore,we introduce an optimization model to maximize the total system revenue,using an iterative algorithm specifically designed to solve complex optimization problems.Numerical simulations demonstrated that the EDRA scheme improved the average network revenue by more than 66%relatively to standard methods,with performance gains increasingly large for an increasing diversity of service types,establishing the robustness and adaptability of the proposed EDRA scheme in the rapidly-evolving context of satellite-based communication systems.
基金co-supported by the National Natural Science Foundation of China(Nos.62473110,62403166)the Fundamental Research Funds for the Central Universities,China(No.2023FRFK02043)+1 种基金the Natural Science Foundation of Heilongjiang Province,China(No.LH2022F023)the National Key Laboratory of Space Intelligent Control Foundation,China(No.2023-JCJQ-LB-006-19)。
文摘With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.
文摘This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.
文摘The sensible and latent heat fluxes over the ocean area near China were calculated and analyzed by usingthe Goddard Earth Observing System (GEOS) - four-dimensional Data Assimilation System (DAS). The calculated results showed that the sensible heat flux had its large value in winter and autumn , small value in spring and summer overthe ocean area near China. In winter, the sensible heat flux increased distinctly with latitude, and its isolines were verycrowded. Over the ocean area east of Taiwan Province and south of Japan, the direction of isoline was from southwestto northeast. In the South China Sea the sensible heat flux was lower than that of surrounding ocean areas,and its isoline was distributed into a type of an inverted trough. In autumn and winter, the maximum center of latent heat flux appeared over the ocean area northeast of Taiwan Province and south and southeast of Japan, meanwhile, the isoline wasin the direction of southwest to northeast. In spring and summer, the latent heat flux had minimum value in the Huanghai Sea. At the same time, the maximum value center of latent heat flux appeared over the ocean area south of Japan inspring.
文摘Scheme of positioning constellation would greatly influence the positioning performance. In this paper, a GEO/HEO hybrid constellation with 3 HEO satellites deployed in 3 orbits and 3 GEO satellites for regional positioning is presented. Firstly, elements for 3 GEO and 3 HEO are optimized from regional visibility for the selected region of interest. Secondly, positioning performance is provided through GDOP(geometric dilution of precision) and PDOP(positional dilution of precision). Simulation results show that similar accuracy with GPS can be gained by this constellation.
