Study On The Evaluation Method Of Visibility Of Airport Traffic Control Tower

Airport Traffic Control Tower(ATCT for short)is the core facility of the operation of civil aviation airport.The location and height of ATCT will directly affect the controller’s observation and judgment of the real-time conditions of the aircrafts and vehicles.The impact of the location and height of ATCTon its visibility at the new and expanded airports are rarely evaluated domesticly all the time,which causes a significant security risk in the airport operation.Therefore,it is extremely necessary to come up with a set of evaluation methods to measure the visibility of ATCT.The rationality of the location and height of ATCT from four aspects is evaluated: visual occlusion of the controller,line of sight angle and two-point lateral discrimination angle,aircraft or vehicle discrimination and flight safety of airports.Firstly,the calculation model based on the maximum slope method is proposed to calculate the visual occlusion range of the controller.Then,the shielding range of Huai’an Airport is calculated with the geometric calculation model and a simulation has been carried out from the perspective of the controller in the three-dimensional model of Huai’an Airport to verify the correctness of the results.Secondly,the geometric calculation models of the line of sight angle and two-point lateral discrimination angle were established.A software was then developed to evaluate whether the line of sight angle and two-point lateral discrimination angle of the key location point are in compliance as well as to verify the key location points of Huai’an Airport are in line with the provisions.Thirdly,the relationship between the visibility and the target(aircraft or vehicle)to background contrast is deduced in certain distance,and a calculation method based on the target transfer probability function is proposed to calculate the probabilities of detection and recognition of aircrafts or vehicles.In the case of Huai’an Airport,the probabilities of detection and recognition of aircrafts or vehicles under different brightness and visibility have beencalculated and analyzed.Finally,the method of assessing the influence of the location and height of ATCT on the safety of the airport operation from the three aspects of the surface of obstacles,flight procedure and aircraft performance has been proposed,which has been used to verify thelocation and height of Huai’an Airport tower,found that the tower location and height of the tower do not cause a security risk in the flight safety of the airport.And the solution to the problem of flight safety of the airportis proposed.Theevaluation method of visibility of ATCT in this paper has been verified in several domestic projects,and works well.