As a result of air traffic demand growth, delay on airport surface increases in congested airports. To mitigate the increased delay, airport expansion programs, in which runways and taxi-ways are expanded, need to be implemented. On the other hand, because the expansion programs require tremendous amount of money and time, prior assessment for the expansion effect is indispensable. Numerous elements including airport layouts and traffic operations need to be covered in the assessment.

Conducting fast time simulation experiments provides valuable information for the prior assessment of airport surface expansion programs in an efficient way. To obtain more reliable information, the simulation experiments should be conducted on valid models. Validation process for simulation models is thus required. In consideration of aspects specific to modeled airports, the simulation models should be validated.

A fast-time simulation model of a Japanese airport is introduced in this paper. The modeling process such as operational rules for spot and taxi-way assignment is presented. The validation process of the model follows. Comparing the simulation result with the field observation data, the model is validated and the model proves to yield reliable simulation result. As an application of the simulation model, fast time simulation experiments are conducted on the model. The simulation is to study the consequence of air traffic volume increase on airport surface delay.

At Tokyo International airport, the necessity for a second ASDE site arises for surveillance of the new runway. However, interference became a problem, when the second ASDE was installed as dual site configuration.

Then, the experimental ASDE was installed at Sendai airport and then an interference experiment was carried out between it and the former one at ENRI. The interference experiment by two interfacial wave suppression methods (transmission timing method and stagger/defruiter function) was carried out.

As a result, the interfacial wave was dramatically suppressed by the transmission timing method for delaying the transmission trigger from the trigger of another station in the half-cycle. In addition, the stagger/defruiter function suppressed the interfacial wave from the radar coverage outside where the suppression was impossible in the transmission timing method. By the using interference rejection method of these two jointly, it was possible to suppress all interfacial waves.

Collision risk models are constructed on the basis of hypotheses. If their bases are frail, the calculated risk is no longer reliable. Hence we should inspect models before its application. We focus on two models developed in EUROCONTROL, the kinematical model and the approximation model. They were induced to calculate the horizontal overlap probability of the vertical collision risk formula of aircraft on crossing tracks. We make investigations into their validity in three ways.

One is a theoretical investigation. As a consequence of this investigation, we suggest that the approximation model is an approximation of the kinematical model and this approximation always provides a smaller estimate of risk than the kinematical model.

Another is a numerical calculation. We investigated the case where the model underestimates the risk significantly. We find that two estimations in two ways are almost the same in the low traffic density situation if we choose a small proximity radius; however, it is not the case in the other situations.

The other is an analysis of Japanese radar data. We determine the distribution of the distance between aircraft at the horizontal closest point of approach to ascertain validity of the approximation model. We cannot conclude that the distribution of the proximity distances follows the uniform distribution, which is the fundamental hypothesis of the approximation model.

As a consequence, we concluded that an approximation model should not been applied in Japanese air traffic situation.