Patent ID: 7583223
Filing Date: 2009-09-01
Classification: G01S,G08G

Abstract:
1. A direction finding antenna system located on a first aircraft for determining the relative bearing of a second aircraft from the first aircraft in conjunction with a Traffic Alert Collision Avoidance System (TCAS), the second aircraft being equipped to transmit signals received by the antenna system, the system comprising: a first antenna and a second antenna located on a top surface of the first aircraft, spaced apart along a first axis; a third antenna and a fourth antenna located on a bottom surface of the first aircraft, spaced apart along a second axis orthogonal to the first axis; and a transmitting, receiving, and processing system coupled to the first, second, third, and fourth antennas, wherein the transmitting, receiving, and processing system is configured to transmit TCAS interrogations, receive TCAS replies, and process the TCAS replies to determine the relative bearing of the second aircraft from the first aircraft, wherein the transmitting, receiving, and processing system includes a transmitter selectively coupled to at least one of the first, second, third, and fourth antennas, the transmitter configured to transmit TCAS interrogations omnidirectionally, and wherein each of the first antenna, the second antenna, the third antenna, and the fourth antenna have only a single element.