Patent ID: 6483453
Filing Date: 2002-11-19
Classification: G01S

Abstract:
In an aircraft having a collision avoidance system, a method for interrogating aircraft at extended ranges and for increasing interrogations in crowded airspace, said method comprising:identifying aircraft within a surveillance volume in response to a full power broadcast of a Mode S interrogation; classifying each identified aircraft as either traffic or intruder; maintaining a track for each aircraft; reducing the transmit power of a next Mode S interrogation directed to one of said aircraft; determining whether said one of said aircraft responds to said reduced power transmission of said Mode S interrogation; if said one of said aircraft responds said Mode S interrogation, repeating said maintaining, reducing and determining steps; and if said one of said aircraft fails to respond to said Mode S interrogation, increasing said transmit power of a next Mode S interrogation directed to said one of said aircraft.