In order to evaluate the performance of the proposed method, we construct an experimental scenario oriented to the decomposition of remote sensing tasks based on the self-developed Common Satellite Toolkit (CSTK) simulation platform. The CSTK platform calculates the real-time positions and orbits of the satellites within a 3D scenario for the satellite’s TLE data and assigns a unique computation, storage, and observation payload resource to each satellite for mission execution.
5.1. Simulation Scenario and Dataset Details
This scenario simulates the task of remote sensing data decomposition and allocation in a dynamic satellite network, with a duration from 04:00:00.00 UTC on 3 September 2024 to 04:00:00.00 UTC on 5 September 2024.
When constructing remote sensing tasks, we thoroughly considered the satellites’ operational status and the target area’s geographical characteristics. Each remote sensing task is represented as a structured data unit designed to facilitate efficient scheduling and resource allocation in a dynamic satellite network. The dataset captures both the satellites’ operational status and the target areas’ geographical characteristics, enabling accurate imaging and timely task execution. The main fields include the task ID, satellite ID assigned to the task, task time window, target area, expected data volume, task priority, and task dependencies. Regarding the target area, we describe it in the form of latitude and longitude ranges, clearly specifying the minimum and maximum latitude and longitude of the imaging area to ensure accurate coverage of the predetermined area during task execution. The “task dependency relationship” field clearly describes the sequential dependencies between the current task and other tasks.
Specifically, in each task, the observable angle and altitude requirements between the satellite and the target area are determined through precise calculations based on the satellite’s orbit information and ground station position. We use a formula to calculate the observation angle that meets the minimum elevation angle requirement, in order to derive the most suitable imaging time window. Subsequently, we set different priorities for each task based on its importance and resource consumption. The resource requirements of the task are mainly reflected in the working status of the imaging payload and the data transmission requirements. During the task execution process, the satellite needs to complete multi-stage operations such as data acquisition, compression, and transmission in real time, and each stage has strict time and resource limitations.
To further illustrate the structure of the task dataset used in this study,
Table 1 provides a more detailed breakdown of actual task instances, including task IDs, target observation regions, discrete time ranges, and resource requirements. The interface for adding remote sensing tasks is shown in
Figure 2.
We combined precise satellite data and using the CSTK simulation platform to construct a real multi-satellite network environment. The actual dataset was constructed using precise satellite data from multiple authoritative platforms, including Celestrak (CELESTRAK same as below. satellite database:
https://celestrak.org/) and SatNOGS (SatNOGS open-source ground station network:
https://satnogs.org/). Celestrak provides precise orbit parameters (comprising the semi-major axis, eccentricity, inclination, ascending node longitude, and perigee angle) that meet the standards of the North American Aerospace Defense Command, ensuring reliable orbit information. SatNOGS provides detailed ground station observation data, such as coordinates and communication link status.
This dataset covers various key parameters in satellite networks, including the computing, storage, and payload resources of each satellite, as well as task identification, subtask details, task time windows, task priorities, and resource requirements in task data. Specifically, the satellite data section provides a detailed record of the resource distribution of each satellite. The task data section decomposes each remote sensing task into several subtasks, which not only indicate the type (such as observation or compression), priority, and required resources, but also clearly define the start and end time windows of the task and the dependencies between tasks. As shown in
Table 2, we can intuitively understand how the dataset comprehensively reflects the satellite orbit characteristics, resource distribution, and key parameters in task scheduling.
In order to evaluate the performance of this paper under each evaluation metric, we conducted simulation experiments on 14 datasets with different numbers of satellites and numbers of missions.
Table 3 shows the details of the datasets used for the experiments.
5.2. Comparative Algorithm and Performance Metrics
To address the problem’s characteristics of temporal variation, complex resource allocation, block structure preservation, network delay, and hierarchical scheduling, we select five comparative algorithms: Optimizing Scheduled Virtual Machine Requests Placement in Cloud Environments: A Tabu Search Approach (TS-SVMPP) [
31] with time complexity
; Cooperative Mapping Task Assignment of Heterogeneous Multi-UAV Using an Improved Genetic Algorithm (IDCE-GA) [
30] with time complexity
(in the genetic algorithm,
P represents the population size in each generation, and
G represents the number of generations); MILP-StuDio: MILP Instance Generation via Block Structure Decomposition (MILP-STUDIO) [
25] with time complexity
; Resource Allocation Considering Impact of Network on Performance in a Disaggregated Data Center (RA-CNP) [
29] with time complexity
; and Task Decomposition and Hierarchical Scheduling for Collaborative Cloud–Edge–End Computing (VNE-AC) [
36] with time complexity
. In addition, the HEFT-LA algorithm [
26] is included in the scheduling category with time complexity
, which improves task execution efficiency through a lookahead variant, and the PA-LBIMM algorithm [
32] with time complexity
, which integrates user-priority-based Min-Min scheduling to enhance load balancing. These algorithms are commonly used to solve resource allocation and scheduling problems and have efficient optimization effects. TS-SVMPP and IDCE-GA are often used to optimize virtual machine placement and UAV task allocation, demonstrating good adaptability, while MILP-STUDIO, RA-CNP, and VNE-AC exhibit strong optimization capabilities in large-scale and dynamic environments.
For performance evaluation, we employ the following metrics. Task execution rate
is calculated using the equation
which evaluates the proportion of successfully executed tasks. The objective function value defined in Equation (
19) is used to quantify the overall optimization effect of the system. Additionally, resource utilization
serves as a metric to evaluate the efficiency of resource allocation, defined as
To measure communication costs, we introduce the following metrics:
where
represents the communication cost for task
in the communication resource request, and
represents the total communication capacity of the resource. This metric reflects the communication cost incurred during the execution of tasks, with lower values indicating better communication efficiency. The CC helps evaluate the optimization of communication resources and their impact on the overall system.
In addition, our evaluation criteria also include EQ (task execution quality, where higher values indicate better completion), UQ (execution uncertainty, where lower values indicate smaller errors or delays), and SR (success rate, measured as the ratio of executed tasks to total tasks, expressed as a percentage).
5.3. Numerical Analysis
For each dataset, we performed multiple executions to ensure the robustness and stability of the algorithm, facilitating subsequent comparison and analysis. Our data is based on simulated and synthetic data, reflecting remote sensing satellite tasks in the real world, providing insights into the performance of algorithms in real-world environments.
Figure 3 provides the objective function values and optimization trends for 14 datasets, offering a detailed view of the performance of each algorithm at different task scales. From
Table 4, it can be seen that HADRM consistently produces lower objective function values in larger-scale scenarios. For example, in dataset D12, the value of HADRM is 1,523,658, while the value of IDCE-GA is 2,254,874, a decrease of approximately 32.4%. In dataset D14, the value of HADRM2038836 increases by nearly 44.7% compared to the 3,685,412 reported by IDCE-GA. These quantitative differences highlight the enhanced ability of HADRM in managing large-scale complex task environments.
The outstanding performance of HADRM can be attributed to its hierarchical adaptive decomposition and reinforcement learning-based resource mapping mechanism. Specifically, HADRM dynamically decomposes complex task sets into smaller subproblems, simplifying scheduling and reducing computational overhead. Its reinforcement learning component continuously adjusts resource mapping decisions in real time based on constantly changing network conditions and task dependencies. This integrated, data-driven approach enables HADRM to quickly adapt and maintain efficient resource allocation, even in the face of a surge in workload.
In contrast, IDCE-GA and TS-SVMPP, although they perform reasonably in medium-sized scenarios, lack this dynamic adjustment capability. This limitation makes it difficult for them to maintain stable optimization when the task load increases. Similarly, MILP-STUDIO and RA-CNP rely on complex integer programming formulas, which can lead to a rapid increase in computational overhead in large-scale environments. Although VNE-AC sometimes produces competitive results in smaller networks, its static scheduling mechanism limits its adaptability to rapidly changing conditions in a wider and more complex environment. Though HEFT-LA and PA-LBIMM perform reasonably well, they still do not achieve the same level of optimization as HADRM. HEFT-LA lacks the dynamic resource mapping of HADRM, making it less effective in large-scale, dynamic environments. PA-LBIMM, while incorporating user-priority awareness, relies on static scheduling, limiting its adaptability in complex, fluctuating conditions.
Table 5 shows the resource utilization percentages of each algorithm at different task scales, providing us with a detailed quantitative evaluation. For example, in dataset D14, the resource utilization rate of HADRM reached 77.5143%, higher than IDCE-GA’s 53.2478% and TS-SVMPP’s 62.8745%; in dataset D10, the resource utilization rate of HADRM reached 92.2541%, which is also better than the other comparative algorithms. These data fully demonstrate the ability of HADRM to more efficiently utilize available resources in large-scale complex task environments.
As shown in
Figure 4a, we first evaluate each algorithm’s resource utilization in a static scenario by gradually increasing the task size. The results indicate that HADRM consistently maintains a high utilization rate, reflecting its advantage in real-time resource allocation as the task size grows.
Next, to investigate how the iteration count affects performance, we conduct a parameter-tuning experiment. Specifically, we adjust the number of iterations and observe the algorithms’ dynamic changes in resource usage. As illustrated in
Figure 4b, HADRM continues to achieve the highest utilization among all methods over successive iterations, demonstrating robust and adaptive resource allocation under changing workload conditions.
Its excellent performance is mainly attributed to its hierarchical adaptive decomposition and reinforcement learning-based resource mapping mechanism. Specifically, HADRM simplifies the scheduling process and reduces computational overhead by dynamically decomposing complex task sets into more manageable subproblems; meanwhile, its reinforcement learning module can adjust resource allocation decisions in real time based on constantly changing network conditions and task dependencies.
However, although IDCE-GA and TS-SVMPP perform well in medium-scale scenarios, they lack the necessary dynamic adjustment capabilities, making it difficult for them to maintain stable optimization effects when task loads increase; however, MILP-STUDIO and RA-CNP rely on complex integer programming methods, leading to a rapid increase in computational overhead in large-scale environments. In addition, the static scheduling mechanism of VNE-AC also limits its adaptability in rapidly changing and complex environments. Although HEFT-LA and PA-LBIMM performed well, especially the PA-LBIMM algorithm, which showed competitive results in multiple datasets, HADRM maintained more balanced and efficient resource utilization overall.
As shown in
Table 6 and
Figure 5a, we measure the task execution time of each algorithm at different task scales, providing a comprehensive quantitative comparison. From these results, it is evident that algorithms such as MILP-STUDIO and TS-SVMPP perform well in small-scale datasets with shorter execution times; however, as the task scale increases, HADRM demonstrates notable advantages. For example, in dataset D14, the execution time of HADRM is 29,652.15, which is substantially lower than MILP-STUDIO’s 37,254.12 and the times of IDCE-GA and TS-SVMPP, both around 39,874.12.
Next, to investigate how the iteration count affects task execution time, we conducted a parameter-tuning experiment. As shown in
Figure 4b, HADRM not only achieves lower execution times, but also converges more rapidly over successive iterations, indicating that in large-scale, complex task scenarios, HADRM can more efficiently handle task scheduling and resource allocation.
The advantage of HADRM lies in its adoption of a scheduling strategy that integrates hierarchical adaptive decomposition and reinforcement learning. Specifically, HADRM reduces the dimensionality of problems by decomposing large-scale complex tasks into multiple easily manageable subtasks, and utilizes reinforcement learning modules to monitor network status and task dependency changes in real time, dynamically adjusting scheduling strategies and effectively shortening overall execution time. In contrast, IDCE-GA is based on genetic algorithms, and its evolutionary process converges slowly and is prone to becoming stuck in local optima, making it difficult to search for global optimal solutions in a timely manner when facing large-scale tasks. Although TS-SVMPP uses tabu search to improve local optimization, the search space rapidly expands when the number of tasks increases, resulting in a significant increase in computational burden. MILP-STUDIO relies on integer programming for solving, and its computational complexity increases exponentially, leading to a sharp increase in computation time in large-scale scenarios. RA-CNP adopts a static network performance model, and the scheduling strategy lacks responses to real-time changes in task load and network status. The fixed static scheduling mechanism of VNE-AC cannot effectively cope with the dynamic changes in task dependencies in complex environments, and its overall scheduling efficiency is greatly limited.
For clarity of presentation, we conducted experiments on all 14 datasets but only show representative results for four of them in this table. The
Table 7 provides a detailed display of two key metrics for task execution for each algorithm in four datasets (
–
). From the table, it can be seen that HADRM achieved the best performance in all datasets. For example, in dataset
, HADRM’s EQ reached 78 and its UQ was only 2, significantly better than those of IDCE-GA (EQ 75, UQ 5), TS-SVMPP (EQ 77, UQ 3), MILP-STUDIO (EQ 76, UQ 4), and VNE-AC (EQ 73, UQ 7). In dataset
, HADRM led again with EQ 146 and UQ 14. In datasets
and
, HADRM achieved EQs of 215 and 264, respectively, while its UQs were only 25 and 36. These data fully demonstrate the advantages of HADRM in terms of task execution quality and stability.
The trend of task execution rate in
Figure 6 further illustrates the dynamic changes in the performance of various algorithms at different task scales. From the graph, it can be seen that as the task size increases, and HADRM consistently maintains high execution quality and low uncertainty, demonstrating its ability to effectively schedule tasks and reduce errors in high-load environments. This outstanding performance is mainly attributed to the advanced task decomposition and real-time scheduling mechanism adopted by HADRM, which can dynamically split complex tasks into manageable subtasks and flexibly adjust scheduling strategies based on real-time feedback, thereby ensuring efficient and stable execution in large-scale task environments.
In contrast, IDCE-GA relies on traditional genetic algorithms, while TS-SVMPP introduces tabu search to improve local optimization, but the search space rapidly expands when the task size increases. The integer programming method used by MILP-STUDIO has high computational complexity, while RA-CNP is limited by static network models, and the fixed scheduling mechanisms of VNE-AC cannot easily balance efficiency and low uncertainty in large-scale complex environments. HEFT-LA and PA-LBIMM demonstrate competitive performance in terms of makespan and resource utilization but still fall behind HADRM. While they offer improvements in load balancing and user-priority handling, their task execution time and resource utilization are less optimized compared to HADRM’s more efficient scheduling. This is mainly due to the lack of dynamic task mapping in HEFT-LA and the trade-off between VIP and ordinary tasks in PA-LBIMM.
Figure 7 presents the normalized communication cost across all 14 datasets for each algorithm. From the graph, it is clear that HADRM consistently outperforms the other algorithms in minimizing communication cost, especially in large-scale environments. For example, in dataset
, HADRM reduces the communication cost by approximately 2% compared to IDCE-GA, and by over 4% compared to MILP-STUDIO. Additionally, in the dataset
, HADRM achieves a significant reduction of around 5% compared to PA-LBIMM, and a 3% improvement over RA-CNP. These results highlight HADRM’s superior efficiency in managing communication resources, especially when task scale increases.
In contrast, algorithms like IDCE-GA and TS-SVMPP, although they perform well in certain datasets, exhibit a higher communication cost due to the inefficiencies in their communication scheduling mechanisms. Similarly, RA-CNP and VNE-AC struggle with communication overhead, while HEFT-LA and PA-LBIMM, though competitive in some aspects, still lag behind HADRM. This is primarily due to HADRM’s advanced dynamic resource mapping and task scheduling mechanisms, which optimize both task execution and communication cost effectively in large-scale environments.