Abstract: With the opening of carbon trading market, safety operation and development of energy-saving emission reduction technology have become focuses of airline operation. A method of identifying the optimal flight level basing on flight data from airlines is presented. By analyzing the spatial characteristics of flight trajectory, difference matrix model basing on Hausdorff distance is established. The kernel density estimation method is used to degree identify prevalent flight trajectory. According to the relationship between flight path and flight level, a refined method of flight level identification is proposed. Finally, taking ZGNN-ZSNJ flight data of an airline as example,the optimal flight level can be effectively distingnished; meanwhile, the safety and economy of the current method is verified.

Key words: air traffic flow, flight level, kernel density estimation, energy-saving and emission-reduction