1. College of Mechanical Engineering, Beijing Information Science and Technology University,Beijing,China
2. Tsinghua University,Department of Automation,Beijing,China
3. Second Research Institute of Civil Aviation Administration of China,Chengdu,China
4. Civil Unmanned Aircraft Traffic Management Key Laboratory of Sichuan Province,Chengdu,China
5. Beijing National Research Center for Information Science and Technology, Tsinghua University,Beijing,China