Fast lightweight reconfiguration of virtual constellation for obtaining of earth observation big data

Earth observation (EO) big data is playing the increasingly important role in spatial sciences. To obtain adequate EO data, virtual constellation is proposed to overcome the limitation of traditional EO facilities, by combining the existing space and ground segment capabilities. However, the current configuration pattern of virtual constellation is tightly coupled with the specific application requirements. This leads to the costly reconfigurations. Although the pattern of software defined satellite network can decouple topology reconfigurations from application requirements, it cannot be directly applied to the reconfigurations of virtual constellations because of some drawbacks. To address the problem, we propose a model of LEO-ground links control-covering (LGLC) to implement fast and lightweight reconfiguration for virtual constellation. LGLC uses a bipartite graph model to formalize the dispatch problem of the control information of virtual constellation reconfiguration, and the optimum solution can be got by the classical algorithm in polynomial time. According to the strategy obtained, only if a few satellites and stations receive the control information, virtual constellation can be reconfigured quickly. We also establish some metrics to evaluate the effect of LGLC. Extensive experiments are conducted to confirm the above claims.