DMTRH: A Real-Time Scheduling Algorithm for Multiple Earth Observation Satellites

Currently, most tasks submitted to earth observation satellites (EOSs) are with deadlines, to satisfy users' timing requirements. Especially, in emergency, the timing needs are more apparent. Unfortunately, traditional scheduling algorithms do not efficiently deal with this issue. Hence, it is nontrivial to propose a real-time scheduling algorithm for multiple EOSs. In this paper, we establish a multi-objective mathematic programming model for real-time scheduling of EOSs. To improve user's revenue and resource utilization, a task dynamic merging strategy is proposed. With the dynamic merging in place, plus consideration of retracting and rearranging some scheduled tasks to make room for incorporating the newly arrived tasks, we present a novel real-time scheduling algorithm -- DMTRH. To demonstrate the superiority of our DMTRH, we conduct extensive experiments by simulations to compare DMTRH with two algorithms -- RHTSS and STI. The experimental results indicate that DMTRH improves the scheduling quality of others and is suitable for realtime scheduling.