An approach for pre-scheduling of earth observing satellites

The EOSs (Earth Observing Satellites) circle the earth to take shots that are requested by customers. But the resource of the EOSs is relatively limited compared to the user requests. Considering the constraints of EOSs, to make replete use of the resource and reduce the scheduling time of planning the requests, it is required to deal with the conflicting requests which can be shot by more than one EOS. We adopt the label vertex digraph without circuit to present the relations and the attribute of the requests as the model of the scheduling of the EOSs. On the basis of the model of the scheduling, we also propose a prescheduling algorithm which uses the probability of the shot to assign the conflicting requests. Therefore the scheduling problem of the EOSs is transformed to the scheduling problem of respective EOS. And the complexities of the problem reduce greatly.