Heuristic Scheduling Algorithm Oriented Dynamic Tasks for Imaging Satellites

Abstract

Imaging satellite scheduling is an NP-hard problem with many complex constraints. This paper researches the scheduling problem for dynamic tasks oriented to some emergency cases. After the dynamic properties of satellite scheduling were analyzed, the optimization model is proposed in this paper. Based on the model, two heuristic algorithms are proposed to solve the problem. The first heuristic algorithm arranges new tasks by inserting or deleting them, then inserting them repeatedly according to the priority from low to high, which is named IDI algorithm. The second one called ISDR adopts four steps: insert directly, insert by shifting, insert by deleting, and reinsert the tasks deleted. Moreover, two heuristic factors, congestion degree of a time window and the overlapping degree of a task, are employed to improve the algorithm’s performance. Finally, a case is given to test the algorithms. The results show that the IDI algorithm is better than ISDR from the running time point of view while ISDR algorithm with heuristic factors is more effective with regard to algorithm performance. Moreover, the results also show that our method has good performance for the larger size of the dynamic tasks in comparison with the other two methods.

Imaging-Duration Embedded Dynamic Scheduling of Earth Observation Satellites for Emergent Events

“…In addition to the objective of high revenue, we have to consider the robustness of the scheduling scheme SS. Usually the dynamic scheduling problem needs to satisfy two objectives: to maximize the revenue and to minimize the perturbation to the previous scheduling [19,20].…”

“…In practice, satellite scheduling is a complicated process. A certain amount of time is required to upload an instruction to a satellite with special equipment within limited visible time windows [19,20]. Once the scheduling scheme is modified on a large scale, there may be a series of influences on the decision of users.…”

“…. , | |] do (16) for all scheduled tasks in SS do (17) if can be merged with the time window of a scheduled task (18) construct a compact composite task between and (19) r e m o v et a s k from (20) g o t os t e p( 8) (21) endif (22) endfor (23) end for (24) (25) if can be inserted into SS directly do (26) insert and determine the earliest start time ES and the latest start time LS of (27) removetask from (28) gotostep ( Figure 12(a) that tasks and must be located in the same swath of the sensor.…”

“…Sun et al described the dynamic scheduling problem as a dynamic weighted maximal constraint satisfaction problem in which constraints can be changed dynamically [18]. Wang et al analyzed the dynamic properties of satellite scheduling and proposed two heuristic algorithms to schedule new tasks [19]. Wang et al described the dynamic scheduling problem with a unified form of inserting new tasks.…”

Satellite constellation design for forest fire monitoring via a stochastic programing approach

“…Researchers have examined the general problem of task scheduling for satellites after a natural disaster using heuristics (Wang, Dai, & Vasile, ) as well as robust methods (Zhai, Niu, Tang, Wu, & Shen, ). There have been works that investigated the tradeoff between observation time and fuel usage (Zhu, Li, & Baoyin, ) after a disaster and as part of mission design (Hoskins & Atkins, ), but these works assumed prior knowledge about the state of the system that would not be known before a disaster occurs.…”