EP0249493A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Aircraft collision warning system
Assignee: Raytheon Systems Ltd
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Filing: 1987-06-12
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Granted: —
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Expires: 2007-06-12
Abstract
Abstract Each aircraft is fitted with two antenna units (A1, B1 and A2, B2) laterally spaced by a distance S and each comprising longitudinally spaced sharksfin radiators. The two antenna units are energised together to transmit a directional interrogation pulse (P1/P3) into the airspace forward of the aircraft. An intermediate sidelobe suppression pulse (P2)is transmitted from a non-directional antenna (C). Each aircraft is also equipped with a transponder and an aircraft correctly interrogated by the interrogation pulse sends a reply. The reply is received at the two antenna units of the interrogating aircraft. The round time delay enables the range of the responding aircraft to be determined while the relative phases of the reply at the two antennas enable the azimuth of the aircraft to be determined interferometrically. Information gathered in this way is processed to detect aircraft on potential collision courses and these are shown on a display device. An audible warning is given to alert the pilot to any aircraft which is close and on a potential collision course.
Inventors
- 👤 Brian Walter Watson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 14:50
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/88; G01S13/93; G01S13/933
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
142 words
An aircraft collision warning system for use with aircraft equipped with transponders, comprising two laterally spaced antenna units (A1, A2 and B1, B2) mounted on an aircraft, an interrogating transmitter (11) arranged repeatedly to transmit interrogating signals by way of at least one of the antenna units into the airspace ahead of the aircraft, a receiver (12) arranged to receive and process transponder replies reaching the two antenna units so as to provide range information in dependence upon the delay between an interrogating signal and a reply thereto and bearing information in dependence upon the relative phases of the reply at the two antennas, and display means (14) responsive to the range and bearing information to show the position of an aircraft in the airspace ahead of the aircraft which has given rise to a reply and is a potential collision hazard.
Claim 2
Dependent Claim
142 words
An aircraft collision warning system for use with aircraft equipped with transponders, comprising two laterally spaced antenna units (A1, A2 and B1, B2) mounted on an aircraft, an interrogating transmitter (11) arranged repeatedly to transmit interrogating signals by way of at least one of the antenna units into the airspace ahead of the aircraft, a receiver (12) arranged to receive and process transponder replies reaching the two antenna units so as to provide range information in dependence upon the delay between an interrogating signal and a reply thereto and bearing information in dependence upon the relative phases of the reply at the two antennas, and display means (14) responsive to the range and bearing information to show the position of an aircraft in the airspace ahead of the aircraft which has given rise to a reply and is a potential collision hazard.
Claim 3
Dependent Claim
20 words
A system according to claim 1, wherein each antenna unit comprises at least one sharksfin radiator (A1, A2, B1, B2).
Claim 4
Dependent Claim
42 words
A system according to claim 1 or 2, wherein each antenna unit comprises a plurality of longitudinally spaced radiators (A1, A2 and B1, B2) with feedline delays (16) such as to bring the signals pertaining thereto into phase in the antenna channel.
Claim 5
Dependent Claim
43 words
A system according to claim 1, 2 or 3 wherein the receiver comprises a correlator network (22) which processes the RF signals from the two antenna units to provide in-phase and quadrature outputs proportional to the sine and cosine of the bearing angle.
Claim 6
Independent Claim
21 words
A system according to claims 1 to 4, comprising alarm means which provide an alerting alarm when a collision hazard exists.
Claim 7
Dependent Claim
14 words
A system according to claim 5, wherein the alarm means provide an audible alarm.
Claim 8
Independent Claim
19 words
A system according to any of claims 1 to 6, wherein each aircraft is equipped with an IFF transponder.
Claim 9
Independent Claim
57 words
A system according to any of claims 1 to 7, wherein the aircraft is further equipped with a non-directional antenna (C) and the interrogating transmitter transmits an interrogating pulse (P1) on the sum pattern of the two antenna units (A1, A2 and B1, B2) and a sidelobe suppression control pulse (P2) by way of the non-directional antenna.
Claim 10
Dependent Claim
162 words
An aircraft collision warning system for a plurality of aircraft wherein each aircraft is equipped with a transponder, two laterally spaced antenna units (A1, A2 and B1, B2), an interrogating transmitter (11) arranged repeatedly to transmit interrogating signals by way of at least one of the antenna units into the airspace ahead of the aircraft, a receiver (12) arranged to receive and process transponder replies reaching the two antenna units so as to provide range information in dependence upon the delay between an interrogating signal and a reply thereto and bearing information in dependence upon the relative phases of the reply at the two antennas, and display means (14) responsive to the range and bearing information to show the position of an aircraft in the airspace ahead of the aircraft which has given rise to a reply and is a potential collision hazard, wherein any one of the said aircraft may detect any other one of the aircraft as a collision hazard.
Claim 11
Dependent Claim
162 words
An aircraft collision warning system for a plurality of aircraft wherein each aircraft is equipped with a transponder, two laterally spaced antenna units (A1, A2 and B1, B2), an interrogating transmitter (11) arranged repeatedly to transmit interrogating signals by way of at least one of the antenna units into the airspace ahead of the aircraft, a receiver (12) arranged to receive and process transponder replies reaching the two antenna units so as to provide range information in dependence upon the delay between an interrogating signal and a reply thereto and bearing information in dependence upon the relative phases of the reply at the two antennas, and display means (14) responsive to the range and bearing information to show the position of an aircraft in the airspace ahead of the aircraft which has given rise to a reply and is a potential collision hazard, wherein any one of the said aircraft may detect any other one of the aircraft as a collision hazard.
Claim 12
Dependent Claim
31 words
A system according to claim 9, wherein the transponders are IFF transponders and the interrogating transmitters (11) and the receivers (12) are arranged to operate in conjunction with these IFF transponders.
References Cited (Backward Citations)
No citation records indexed.
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