The Study Of Surveillance Capacity Of Satellite-based ADS-B System

Satellite-based Automatic Dependent Surveillance-Broadcast(ADS-B)system is an important technical means to achieve wide-area aircraft surveillance.The system deploys receivers in the low-orbit satellite,using the air network of satellites realizes reliable surveillance of aircraft in the world.There is serious co-channel interference in satellite-based ADS-B system,which limits the surveillance performance of the system,so the surveillance performance of satellite-based ADS-B system is focused on.The main work is as follows:One,in order to understand the influencing factors of the surveillance capacity of satellite-based ADS-B system and its internal influencing rules,the method of calculating the surveillance capacity of satellite-based ADS-B system is proposed.The co-channel interference signal model of satellite-based ADS-B receiver is given firstly.Then based on the model,the probability of ADS-B message collision,the probability of ADS-B message correct reception,the update interval of position message are given successively,and the surveillance capacity of satellite-based ADS-B system is given lastly.The correctness of the theoretical calculation is verified by building the simulation system,the study results show that the surveillance capacity of the system is jointly determined by the required update interval of ADS-B application subsystem,the symbol error rate of aircraft-satellite link and satellite-ground link,and the number of satellites.Two,in order to meet the requirement of large surveillance capacity of satellite-based ADS-B system,a multi-beam coverage scheme is proposed,and its receiving performance is given.Firstly,the number of aircrafts in busy airspace is estimated,and based on it the six-beam coverage scheme is given,then the collision-free probability and correct reception probability of the ADS-B message of the six-beam coverage scheme are given according to the similar derivation method.Finally,the position message update interval of the satellite-based ADS-B receiver is given synthetically.The correctness of the theoretical calculation is verified by building the simulation system,the study results show that the proposed six-beam coverage scheme can meet the requirements of large surveillance capacity of satellite-based ADS-B system.