4D Track Displaying Based On Google Earth

By 4D track displaying, the flight track and current position of aircraft can be acquired timely to prevent the aircraft from losing and yawing. Track displaying plays an important role in research on flight conflict, airspace planning, route planning, flight simulation,supporting in air traffic control and air accident investigation. So the quality of aeronautical management can be improved by track displaying technology.Firstly,this paper analyses the demands of track displaying in the base of the format of received automatic dependent surveillance-broadcast(ADS-B) data. In order to display the situation of aircraft truly and fully in the air, this paper calculates some flight parameters of aircraft, such as heading, tilt and color values of track. To prepare sufficient data for subsequent track displaying, flight files are formed by track displaying data stored in Keyhole markup language(KML).Secondly, in order to display the sign of flight, this paper does some researches on the conversion from three-dimensional space coordinate to two-dimensional screen coordinate.The conversion from geographic information system(GIS) coordinate to space rectangular coordinate system is realized at first, and then azimuth rotation matrix, incline matrix and projection matrix are given in the base of the perspective projection theory and graph transformation theory of computer to provide a new projection algorithm for subsequent displaying of flight information.Finally, by the adequate preparation of data, the four-dimensional track displaying system is designed to four main modules. They are data processing module,three-dimensional background module, track display module and the sign displaying module.By development of displaying system in Visual Studio 2005 with interaction between C# and Google Earth, an interactive interface in three-dimensional display environment is formed ultimately in this paper, so that the reliability of air traffic management is enhanced by displaying precision.