Abstract: Abstract: To solve the problem of flight safety that the sustained and rapid growth of air traffic flow leads to, the paper gives a conflict alert algorithm based on ADSB information. The purpose of the algorithm is to find the flight collision which may occur in terminal area or near the airport, and then to provide sufficient time for pilots to take avoiding action. The algorithm is mainly constituted by two models. The first model is flying conflict zoning model which contains the two regions of protected airspace (PAZ) and conflict airspace (CAZ). The second model is the flight conflict detection model which firstly primaries the conflict goal, then detects the possible conflict from both vertical and horizontal directions and issues the appropriate warning information based on the detection result. The large number of MonteCarlo simulation results show that the algorithm is of good performance, the flight conflicts can be effectively found in time, which is of great significance to ensure the security of terminal area or near the airport.

Key words: ADS-B, flight collision, conflict alert