A Dual Filter Scheme for Secondary Surveillance Radar Reply Signals

摘要

In this paper we investigate a channel equalizer that can be used for Secondary Surveillance Radar (SSR) signals present in the area with many reflecting surfaces causing multipath propagation like airports. One of the most widely used surveillance data exchange protocols in ground surveillance is called Mode S or mode "select". In here "select" means that the radar addresses its interrogation to one particular aircraft instead of interrogation all inside the main beam of the radar antenna. Although initially meant to be used solely in air surveillance it has become one of the cornerstones of today's ground surveillance applications used for air traffic control purposes. Because of complex environments, such as airports with high number of reflecting surfaces and Mode S capable transponders, state-of-the-art algorithms must be used to overcome problems and to achieve maximum benefit from using enhanced surveillance systems. In this paper we investigate a channel equalizer for Mode S receiver based on a combination of two adaptive filters.