# A Topological Sensitive Node Importance Evaluation Method in Aerospace Information Networks
## 1 Introduction  
In today's globalized communication era, the ground network cannot meet the communication demands due to natural conditions, therefore the development of a satellite network with global coverage has become an inevitable choice. Compared with terrestrial networks, satellite networks have the advantages of wide coverage and flexible networking [1]. Due to the inherent fragility of the satellite network, nodes or links may fail suddenly. Once a problem occurs, the performance of the entire satellite network may drop sharply or even trigger a domino effect and cause the entire network to be disrupted [2, 3, 4, 5, 6]. Considering the high dynamics of node movement in satellite networks and the diverse connections between nodes, the topology of the network is complex and changeable; therefore, it is of great theoretical and practical significance to study the vulnerability of satellite networks.  
At present, research on the vulnerability of network topology structures has emerged in endless streams. This research has great significance for improving the robustness of the actual system and for designing an efficient system architecture by evaluating and protecting the important nodes. For example, the jumping-surface node method [7, 8, 9], the evaluation model based on the mean square error of the node invulnerability metric value [10], the evaluation method based on node deletion [11, 12, 13, 14], the evaluation method based on natural connectivity [15, 16], and the mutual information method [17], etc. These models and methods have their own characteristics but these research methods are mainly suitable for static networks and have limitations for satellite networks with high dynamics; the evaluation results are not ideal.  
Usually, important nodes play a key role in network functionality and have an important impact on network dynamic processes such as network synchronization and cascadingfaults [18; 19; 20; 21; 22]. Therefore, evaluating the importance of nodes in the network and adopting protection strategies can improve the overall resilience of the network. The importance of a network node is not only related to its local significance but also closely related to its position in the network and the degree of interdependence with other nodes. Based on the above considerations and the node importance contribution, this paper proposes a new method for network node importance evaluation. This method not only considers the contribution of the importance of adjacent nodes and non-adjacent nodes to the evaluated node but also considers the global importance of the node. By combining the global and the local, the node importance evaluation result is more accurate. A metric that characterizes the resilience of the overall network is obtained by using network structure entropy [23; 24].  
The structure of this paper is as follows. In Section 2, we will introduce related works on general network resilience. In Section 3, we propose the node importance transfer probability matrix model. Section 4 will give the survivability evaluation algorithm and Section 5 will carry out a simulation analysis that justifies the feasibility and effectiveness of our method. Section 6 summarizes the paper.