Directed infrared countermeasures (DIRCM) system and method

• US 20070075182A1
• Filed: 10/04/2005
• Published: 04/05/2007
• Est. Priority Date: 10/04/2005
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Fetterly, Donald
• Granted Patent: US 7,378,626 B2
• Time in Patent Office: Days
• US Class Current: 244/3.160
• CPC Class Codes: F41G 5/18 Tracking systems for guns on aircraft
• CPC Class Codes: F41G 7/224 Deceiving or protecting means jamming or anti-jamming of radio-wave systems in general G01S7/36, G01S7/38; defense installations in general F41H11/02; chaff dispensers F42B12/70
• CPC Class Codes: F41H 13/0056 for blinding or dazzling, i.e. by overstimulating the opponent's eyes or the enemy's sensor equipment
• CPC Class Codes: G01S 7/495 Counter-measures or counter-counter-measures using electronic or electro-optical means

Abstract

An agile, high-power, reliable DIRCM system that is easily extended to address sophisticated UV or UV-visible capable multi-band threats includes a missile warner having missile warning receivers (MWRs), one or two-color suitably in the mid-IR range, that detect likely missile launch and pass the threat coordinates to a pointer-tracker having a Roll/Nod gimbal on which the IR laser transmitter is mounted. The pointer-tracker slews the gimbal to initiate tracking based on the threat coordinates and then uses its detector to continue to track and verify the threat. If the threat is verified, the pointer-tracker engages the laser to fire and jam the missile'"'"'s IR seeker. By slewing the gimbal based on unverified threat coordinates to initiate tracking the system is highly agile and can respond to short and near simultaneous MANPADS shots.

Claims

1. A directed infrared countermeasures (DIRCM) system for use on an aircraft to track and jam a missile having an infrared (IR) missile seeker, comprising:

a pointer-tracker mounted on the aircraft, said pointer-tracker having a detector and a Roll/Nod gimbal that includes optics for collecting incident IR radiation and routing it to the detector and an IR laser transmitter mounted thereon;

an IR laser optically coupled to the laser transmitter; and

a missile warner including a receiver that detects a likely missile launch and passes the threat coordinates to the pointer-tracker,

said pointer-tracker slewing the gimbal to the threat coordinates to initiate tracking and then processing the data from its detector to refine tracking of and verify the threat, and, if verified, engage the IR laser to emit a modulated IR laser beam through the laser transmitter to jam the IR missile seeker.

2. The DIRCM system of claim 1, wherein the missile warner includes a one-color receiver.

3. The DIRCM system of claim 1, wherein the warner receiver and pointer-tracker detector sense in the MWIR band.

4. The DIRCM system of claim 1, wherein the point-tracker detector is a two-color detector.

5. The DIRCM system of claim 4, wherein the pointer-tracker two-color detector detects IR radiation in two separate bands between 3 and 5 microns

6. The DIRCM system of claim 4, wherein the two-color pointer-tracker processes the data to refine tracking and verify the threat by application of a two color algorithm that exploits the differences in spectral content and scene dynamics between a missile and background clutter.

7. The DIRCM of claim 1, further comprising a continuous optical fiber that optically couples the laser to the laser transmitter.

8. The DIRCM of claim 7, wherein the Roll/Nod gimbal slews around a roll-axis and a nod-axis to track the target, wherein the continuous optical fiber is routed from the laser, around a gimbal pivot and off the Roll and Nod axes and to the laser transmitter.

9. The DIRCM of claim 1, wherein the Roll/Nod gimbal slews around a roll-axis and a nod-axis to track the target, said IR transmitter is mounted on the gimbal off the Roll/Nod axes.

10. The DIRCM of claim 9, wherein the gimbal includes a dome, further comprising conformal optics that reduce the aberration of the off-axis laser through the dome.

11. The DIRCM of claim 8, further comprising:

a UV/visible laser;

a UV/visible laser transmitter mounted on the gimbal; and

a second continuous fiber that couples the UV/visible laser to the UV/visible laser transmitter.

12. The DIRCM of claim 11, wherein the UV/visible laser operates between 0.28 microns and 0.7 microns.

13. The DIRCM of claim 11, wherein the IR and UV/visible laser transmitters are the same said laser transmitter.

14. The DIRCM of claim 11, wherein the IR and UV/visible transmitters are mounted on a gimbal off-axis from the gimbal Roll/Nod axes, further comprising conformal optics that reduce the aberration of the off-axis lasers through the DIRCM dome.

15. A directed infrared countermeasures (DIRCM) system for use on an aircraft to track and jam a missile having an infrared (IR) missile seeker, comprising:

a pointer-tracker mounted on the aircraft, said pointer-tracker having a detector and a Roll/Nod gimbal that includes optics for collecting incident IR radiation and routing it to the detector and an IR laser transmitter mounted thereon;

an IR laser;

a continuous optical fiber that is routed around the Roll/Nod gimbal axes to optically couples the IR laser to the laser transmitter; and

a missile warner including multiple receivers that detects a missile launch and passes the threat coordinates to the pointer-tracker,

said pointer-tracker slews the gimbal to the threat coordinates, processes the data from its detector to fine tracking and engages the IR laser to emit a modulated IR laser beam through the laser transmitter to jam the IR missile seeker.

16. The DIRCM of claim 15, wherein the missile warner passes threat coordinates of a likely but unverified missile launch, said pointer-tracker slews the gimbal to the threat coordinates to initiates tracking and further processes the data from its detector to verify the threat before engaging the IR laser.

17. The DIRCM of claim 16, wherein the pointer-tracker detector is a two-color tracker.

18. The DIRCM of claim 15, further comprising:

a UV/visible laser;

a UV/visible laser transmitter mounted on the gimbal; and

a second continuous fiber that is routed around the Roll/Nod gimbal axes to couple the UV/visible laser to the UV/visible laser transmitter.

19. A method of directed infrared countermeasures (DIRCM) for using a pointer-tracker having a Roll/Nod gimbal mounted on an aircraft to track and jam a missile having an infrared (IR) missile seeker, comprising:

Collecting incident IR radiation in a wide FOV;

Declaring likely missile launch based on the collected IR radiation;

Passing threat coordinates for the missile launch to the pointer-tracker;

Slewing the Roll/Nod gimbal to the threat coordinates to initiate tracking;

Collecting incident IR radiation in a narrow FOV through the gimbal to refine tracking of and verify the threat; and

If verified, engaging an IR laser to emit a modulated IR laser beam to jam the IR missile seeker.

20. The method of claim 19, further comprising:

transmitting the IR laser beam through a continuous fiber that is routed around the Roll/Nod gimbal axes to a gimbal transmitter.

21. The method of claim 20, further comprising:

transmitting a UV/visible modulated laser beam through a second continuous fiber that is routed around the Roll/Nod gimbal axes to a gimbal transmitter.

22. The method of claim 19, wherein the IR radiation collected in the narrow FOV is detected in two colors and verified using two-color algorithms.