METHOD AND DEVICE FOR FILTERING REPLIES IN A SECONDARY RADAR EXTRACTOR

摘要

The present invention relates to the filtering of replies received by an extractor located downstream from a secondary radar receiver. On aim of the invention is to provide a defruiter which can take into account carriers whose radial speed is greater than that of secondary radar. According to the invention, a first reply received during a recurrence I is considered as being synchronous with a second response reply received during another recurrence j if rhoj∈[rhoi -Vmax x (t j - ti); rhoi- - Vmin x (t j - ti)] when tj >ti, or rhoj∈ [rhoi -Vmin x (tj - ti); rhoi- - Vmax x (tj -ti )] when tj <ti, or Vmin and Vmax are respectively the minimum and maximum radial speed of the transponders in relation to the secondary radar, positive by convention for a transponder moving closer to the radar, Vmin, and Vmax being able to be equal, at least Vmin or Vmax being non null; rhoi and rhoj are respectively the distance at which the transponder has been detecting in recurrence i and recurrence j; ti and tj are respectively the moment of transmission of the query in recurrence i and recurrence j. The defruiter according to the invention can comprise a single synchronous filter (wherein Vmin = -Vmax for example) or a set of filters functioning in parallel, whereby each filter treats different radial speed segments.