Study On Long-term Forecasting Methods Of Air Traffic Flow

Air traffic flow management (ATFM) is an important part of air traffic management (ATM). Along with the development of economy, the country's air traffic flow also continued a rapid growth. Long-term scientific and accurate forecasts of air traffic flow is not only a basis for all levels of ATM decision-making to make development strategies and planning, but also an effective pledge to sustained and broadened air traffic flow. The main new ideas are as follows:Through the analytical result of recently history data of ATF and some research results, the models which are suitable for forecasting air traffic flow are established based on the theories of gray and stochastic statistics.The Gray forecast method and the Markov forecast method are combined. The Gray model reveals the current of long-term development of the air traffic flow. The transition of states is determined by the Markov model. So the Gray-Markov model is established.Based on Gray Plane Theory, the group of GM (1,1) models is used to obtain the variation range of the ATF forecasting value in the future. Then on the basis of GM (1, N )model, the gray interval prediction which is based on the GM (1,1)model is broadened and the gray interval prediction model based on the group of GM (1, N )models is established.Considering history data and influence factors, ATF is divided into deterministic flow and stochastic flow. The deterministic flow is shown as the stable growth trend just as exponential curve. The stochastic flow was shown as irregularly fluctuation. In this paper, the stochastic part is considered in the ATF forecasting for the first time. The exponential smoothing model is used to describe the trend part, and the sine function is used to describe the stochastic part. Then the stochastic forecasting model based on exponential smoothing method is established. According to the simulation results of the models which were established in this paper, these models can prejudge the developmental trend of air traffic flow and get better precision results.