Multilateration with ADS-B a boon in civil aviation application

Multilateration (MLAT) system is a technique that can be implemented in tracking military applications and also in an airport environment. This is also considered to be an integral part of A-SMGCS. This technique used for obtaining surveillance data to be combined with other sensors (e.g. SMR). This redundancy of radar sources and information are used to identify the unambiguous track of aircraft or vehicles which are equipped with an operational electronics or equivalent modes of interrogations. Multilateration is the process of locating an object by accurately computing the time difference of arrival (TDOA). The system determines the target location in two (or three) dimensions by solving the mathematical intersection of multiple hyperbolas (or hyperboloids). It is based on the TDOA principle. The Time Difference of Arrival between the two transponder's signals at several receiver sites. For 2D positioning, a minimum of 3 receivers are required (for the principle to work) and for 3D positioning at least 4 receivers are necessary. Since airport surveillance presents a difficult RF environment due to shadowing by buildings and other structures. The paper is generated after studying the open literature and the existing Passive Surveillance Systems marketed in the world. Simulation is carried out for a given location model and derived more accurate target identification. Paper consists of development of mathematical algorithms to determine the exact intersection of hyperbolas which are generated by computing the simultaneous Time Difference of Arrival of the pulse between a pair of Receiving Stations.