Wide area surveillance using SSR mode S multilateration: Advantages and limitations

There is an increasing interest on the various applications of the SSR Mode S (Secondary surveillance radar - mode Selective) for air traffic and airport traffic management. This paper discusses the applications of ICAO standard Mode S signals, in particular in the down link channel around 1090 MHz, to locate and identify cooperating targets in the airport using Multilateration (MLAT) and in the terminal area/en route using Wide Area Multilateration (WAM). Performance analyses and some comparison with the more traditional SSR system (ATC radar beacon system : ATCBRS) are carried out