Optimization-Based Scheduling Method for Agile Earth-Observing Satellite Constellation

Abstract

This Paper proposes a two-step binary linear programming formulation for task scheduling of a constellation of low-Earth-orbit satellites and demonstrates its applicability and scalability to obtain high-quality solutions using a standard mixed-integer linear programming solver. In this instance, the goal of satellite constellation task scheduling is to allocate each task for the satellites and to determine the task starting times in order to maximize the overall mission performance metric. The scheduling problem is formulated to find the solution by first finding a set of candidate communication time intervals for each satellite/ground-station pair as one of the key constraints and time tabling the observation task to acquire the user-requested data, with the incorporation of key constraints for satellite constellation operation. Numerical experiments are designed for investigating the trends, sensitivity, and characteristics of scheduling outputs based on multiple representative instances. The performance of the scheduling solutions by the proposed two-step binary linear programming method exhibits significant improvement of up to 35% in the number of assignments and the sum of profits over the general greedy algorithm.

Spacecraft mission agent for autonomous robust task execution

“…Without the restriction of requiring an autonomous mission manager to reschedule when anomalies are detected, many math-heavy scheduling solutions proving optimality can be found under the topic of Earth Observation Satellite (EOS) scheduling, with a good list of single-satellite approaches referenced in [13]. Similarly, a good list of references for multi-satellite optimal EOS scheduling can be found in [14]. These approaches are focused on proving optimality assuming no autonomy or replanning is required, which can be a valid solution for certain mission scenarios.…”

Task Scheduling of Agile Satellites with Transition Time and Stereoscopic Imaging Constraints

“…This study modifies the authors' previous work [35] and introduces an improved framework for task scheduling of a group of agile satellites taking the images of targets located on the Earth surface with additional consideration of stereo imaging and time-dependent attitude transition time. The mathematical formulation for the scheduling considers the priority of the imaging tasks in its objective function and reflects practically important issues (e.g., the coupling between the task time and required attitude maneuver, data capacity, and stereoscopic imaging) as explicit constraints.…”

“…High attention has been paid on the imaging task scheduling with multiple satellites relatively recently [3,25,[27][28][29][30][31][32][33][34][35]. The review of past studies on scheduling of agile satellite imaging led the authors to identify the opportunity primarily for improving the quality of a schedule solution.…”

Hierarchical Reinforcement-Learning for Real-Time Scheduling of Agile Satellites

“…Related literature mainly carried out on scheduling methods and strategies. Several studies generated the plan on the ground completely and then uploaded it to the satellite system [22]- [24]. In several pieces of literature, the observation plan is generated online.…”