Simulation And Analysis On Data And Protocol Of Ground To Air Surveillance And Communication Of Mode S

Mode S secondary radar(SSR)is a new radar developed upon its current technical standards to overcome the shortcomings of Mode A/C secondary radar.It provides enhanced altitude,identity surveillance and data link capabilities,as well as all the functions of Mode A/C.It can also provide detailed target information of aircraft and to be the data source for the air traffic control automation system.Mode S secondary radar has been widely used in North America and Europe,and is applied more and more in China because of its great advantages.But due to the technical limitations in China,almost all airports and aircrafts,especially on the aircrafts,are equipped with foreign manufacturers.There are two reasons.Firstly,the technical level of Mode S transponder developed in China is low,and there is a gap in the capacity.Secondly,the civil avionics equipment highly requires safety performance and can only be installed on civil aviation aircraft with a TSO.To obtain the airworthiness certificate,it is necessary to ensure that the equipment is technically in conformity with the relevant regulations of the FAA,and that the development process conforms to the corresponding procedures,which raised certain requirements for technic and procedure also,it is necessary to provide the inspection documents according to the requirements of the FAA.The airworthiness certificate can only be obtained after the product is developed according to requirements of FAA and get the submitted documents approved.This study is aimed at solving the above problem.For solving the technical issues,the process of ground-air communication of Mode S is sorted out by the deep understanding of analysis Mode S working principle,which is on the basis of access to the latest version of Minimum Operational Performance Standards for Air Traffic Control Radar Beacon System/Mode Select(ATCRBS/Mode S)Airborne Equipment DO-181 E.The related signal format,data coding and communication protocol are analyzed also,especially detailed in the communication process of 4/5/20/21 and the meaning of the MB field.According to the results of the analysis,the corresponding technical documents and processes are summarized to provide technical support for subsequent prototype development.To solve the problem that how to develop a unit in accordance with the airworthiness procedures,a design and development procedure is summarised from the DO-178(Software Considerations in Airborne Systems and Equipment Certification)and the DO-254(Design Assurance Guidance For Airborne Electronic Hardware).Then the requirements of ground air surveillance communication process are developed according to this procedures.After finishing the requirements development,the ground air surveillance communication process is simulated per VHDL code with Quartus and Modelsim.The ground air surveillance communication process of S model is verified by the testing.In the simulation process,a kind of FPGA device selection method is proposed.By analyzing the simulation test results,the data and protocol of the ground air surveillance communication process in Mode S are verified and correctly understood and implemented,the purpose of this study is achieved well.