Method and apparatus for monitoring the RF environment to prevent airborne radar false alarms that initiate evasive maneuvers, reactionary displays or actions

• US 7,843,375 B1
• Filed: 01/16/2007
• Issued: 11/30/2010
• Est. Priority Date: 01/16/2007
• Status: Expired due to Fees

• Current Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Truver, John P., Rennie, Richard W.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Barker; Matthew M
• Application Number:
  US11/653,522
• Time in Patent Office: 1,414 Days
• Field of Search: 342/14
• US Class Current: 342/16
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: G01S 7/2813 Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00
• CPC Class Codes: G01S 7/36 Means for anti-jamming , e.g. ECCM, i.e. electronic counter-counter measures

Abstract

Rather than costly modifications to existing radars, a small, low cost radar warning receiver is used to monitor the RF environment. This add-on receiver can provide situational awareness including RF signal levels and angle of arrival, and recommend or provide antenna scanning synchronization, blanking inputs or gated reactionary outputs to or for the airborne radar. Utilization of this information can be used to reduce false alarms and improve system performance.

Claims

1. In a airborne warning radar system in which an airborne warning radar is located aboard an aircraft and has a scanning radar antenna, a system for ignoring signals from known RF emitters, comprising:

a radar warning receiver that monitors the RF environment overflown by said aircraft for identifying an RF emitter, for detecting the direction of the source of the RF emitter and for causing the antenna for the airborne warning radar to look away from the specific detected direction, whereby false alarms may be reduced for said airborne warning radar.

2. The system of claim 1, and further including a countermeasure module, wherein said airborne warning radar outputs a countermeasure fire control signal to said countermeasure module for the activation thereof, and wherein said radar warning receiver includes a unit for de-activating the fire control signal coupled to the countermeasure module responsive to a detected known RF emitter, thus to prevent false countermeasure activation.

3. The system of claim 2, wherein said radar warning receiver includes an omnidirectional antenna.

4. The system of claim 1, wherein said radar warning receiver includes a directional antenna, including a directional array for altering the direction of said directional antenna and a signal processing module for ascertaining the direction of said known RF emitter from the direction of said directional antenna.

5. The system of claim 1, wherein said radar warning receiver includes storage for storing the characteristics of known RF emitters and wherein said identifying step includes the steps of detecting the characteristics of an emitter and matching the detected characteristics with the stored characteristics of known RF emitters.

6. A system for lowering the false alarm rate of a primary radar, comprising:

a radar warning receiver operably coupled to said primary radar for detecting and identifying emissions from a non-hostile radar and for causing said primary radar to ignore emissions from a detected known RF emitter, said primary radar including a scanning directional antenna that sweeps out a surveilled area and wherein said radar warning receiver causes said directional antenna to look away from the specific direction of a detected known RF emitter.

7. The system of claim 6, wherein said primary radar, upon detection of predetermined radar returns, generates a countermeasure activation signal and wherein said radar warning receiver, upon detection of a known RF emitter, inhibits the generation of said countermeasure activation signal, whereby false alarms are reduced.

8. The system of claim 6, wherein said primary radar transmits pulses into a surveilled area and wherein said radar warning receiver detects known RF emitters in said surveilled area.

9. A method for reducing the false alarm rate of a primary missile warning radar that scans a surveilled area and activates a countermeasure module upon detection of a predetermined target, comprising the steps of:

coupling a radar warning receiver capable of detecting and identifying known RF emitters in the surveilled area to the primary radar; and

,

causing the primary missile warning radar to ignore signals from detected and identified known RF emitters, the primary missile warning radar including a directional antenna that scans the surveilled area and wherein the step of ignoring signals from known RF emitters includes causing the directional antenna to look away from a specific detected and identified known RF emitter.

10. The method of claim 9, wherein said ignoring step includes the step of inhibiting the operation of the primary missile warning radar to activate the countermeasure module upon detection and identification of a known RF emitter.

11. The method of claim 9, wherein the step of detecting and identifying a known RF emitter includes the step of storing the characteristics of known RF emitters in the surveilled area and comparing the signals from any received emitters to the stored characteristics, such that upon a match an emitter is identified as a known RF emitter.

12. The method of claim 9, wherein the step of inhibiting the primary radar includes the step of interrupting the activation signal to the countermeasure module based on the match.

13. A low-cost, small-sized add-on to a primary airborne radar for the control thereof, comprising:

a radar warning receiver having an antenna adapted to receive signals from emitters within the area surveilled by the primary airborne radar; and

,

a module for inhibiting the primary missile warning radar based on known RF emitters detected and identified by said radar warning receiver,

said primary airborne radar including a directional antenna that is made to sweep said surveilled area and wherein said radar warning receiver produces signals for causing said directional antenna to look away from the specific direction of an identified and detected known RF emitter.

14. The system of claim 13, wherein said primary airborne radar includes a module for generating a countermeasure activation signal and wherein said radar warning receiver includes a unit for inhibiting said countermeasure activation signal upon detection and identification of a signal from a known RF emitter.