Analysis of topological characteristics in air traffic situation networks

In the face of growing demand for air traffic, there is a clear need to measure how difficult a given air traffic situation looks. Currently, the concept of air traffic complexity is usually used to describe the air traffic situation. As yet, not enough work has been done on the between-aircraft proximity from the perspective of structure. This paper proposed a method for description of structural characteristics of air traffic situation based on the theory of complex network, which provides a new clue to precisely describe the air traffic situation complexity. The routinely recorded radar data are collected to construct air traffic situation network with aircraft regarded as node, and the between-aircraft proximity relation as edge. The air traffic situation network under three thresholds were statistically analyzed using network topology indices including degree, edge, connection rate, and network structure entropy. The results show that the inherent structure characteristics can provide an intuitionistic and accessible metrics to measure air traffic situation. For example, node degree can distinguish the key aircraft in the sector; the network connection rate reflects the proximity of aircraft; the network structure entropy reflects the homogeneity of aircraft node degrees.