IL151672A - Protection system against infra-red guided missiles - Google Patents

Description

151672/2 PROTECTION SYSTEM AGAINST INFRARED GUIDED MISSILES 1 151672/2 PROTECTION SYSTEM AGAINST INFRA-RED GUIDED MISSILES FIELD AND BACKGROUND OF THE INVENTION The present invention relates to an improved directional infrared counter measure (DIRCM) system, and more specifically to a method and a system that effectively defeats infrared guided missile threats, especially to aircraft with a large thermal signature.

Since the Second World War one of the primary threat to aircraft has been infrared "heat seeking" guided missiles. Indeed, more than 80% of aircraft that have been shot-down, have been shot down by infrared guided missiles, whether surface-launched (SAM) or air-launched (AAM). In an effort to neutralize this threat, the launching of heat-emitting decoys ("flares") has been widely used. Flares have three primary disadvantages. First, all but the most primitive heat-seeking missiles are unaffected by flares. Second, the time required after missile-launch detection for flare launch and lighting is relatively long when compared to the total time of a typical aircraft/missile engagement. Third, the number of flares a given platform carries at one time is very limited.

In order to defeat the threat of infrared missiles, DIRCM systems have been developed. In Figure 1, the use of early prior art types of DIRCM systems, such as the AN/ALQ-204 by Lockheed-Martin (Owego, New York, USA) is depicted. When a threat 18 is anticipated, the operator of the DIRCM system in a small aircraft 10 activates a lamp 12, illuminating a broad swathe (roughly 40°) with a beam 14 in a direction from which a threat 18 is expected. The iUumination of an infrared seeker 16 of threat 18 by beam 14 causes seeker 16 to be jammed or destroyed, causing threat 18 to miss small aircraft 10. However, the energy density of beams such as 14 has proven to be insufficient to neutralize the infrared seekers of newer missiles.

A system such as the AN/AAQ-24 (V) NEMESIS by Northrop-Grumman Defensive Systems Division (Rolling Meadows, Illinois, USA) is a significant improvement over earlier DIRCM^systems. The operation of such a system is depicted in Figure 2. A MWS (Missile Warning System), such as the AAR-54 (V) by Northrop-Grumman ES3 (Baltimore, Maryland, USA), based on a plurality of detectors 20 mounted on small aircraft 10 detects a missile launch, tracks the launched missile and identifies the missile as a threat 18 to small aircraft 10. The control system of the MWS 22 transfers or "hands-off ' the trajectory of threat 18 to DIRCM control system 24. DIRCM control system 24 then uses dedicated missile tracking system 26 to track threat 18 and directs a light beam 28 (with a width down to about 4°) produced by a gimbaled light source 30 to illuminate threat 18.

An improved DIRCM system similar to that described above and in Figure 2 replaces or supplements gimbaled light source 30 with a laser. Laser DIRCM systems include the AN/AAQ-24 (V) / Viper by Northrop Grumman Defensive Systems Division (Rolling Meadows, Illinois, USA) or the AN/ALQ-212 (ATIRCM) by BAE Systems (Nashua, New Hampshire, USA). In such a DIRCM system, depicted in Figure 3, a laser 32 is used to illuminate threat 18. Due to the narrowness of laser beam 34 produced by laser 32 (less than 3 microradians) dedicated missile tracking system 26 must be highly accurate, being able to identify and pinpoint infrared seeker 16 of threat 18. However, the intensity and wavelength selectivity of laser beam 34 allows for a highly effective, albeit expensive and not robust, DIRCM system. It is important to note that some laser-based DIRCM systems are hybrid systems: a lamp and a coaxial laser 3 151672/2 are used to Oluminate the threat. Although significantly more expensive, such hybrid configurations are often necessary to overcome the likelihood that in real-time engagements the laser cannot be aimed properly for threat neutralization.

An alternative approach is found in the Aero-Gem (Electro-Optical Self-Protection Suite) of Rafael (Israel) which uses a gimbaled wide beam-divergence (between 4° and 10°) light source 36 to illuminate threat 18, as depicted in Figure 4. Different from the DIRCM systems depicted in Figures 2 and 3, the Aero-Gem lacks a dedicated missile tracking system. Once the MWS control system 22 identifies threat 18, the threat trajectory calculated by the MWS control system 22 is used to direct gimbaled light source 36 to illurninate threat 18 with beam 28. The Aero-Gem system is significantly better than other prior-art systems in that no hand-off time is required. The longer Ulumination time gained by eliminating the hand-off time as well as the increased chance for seeker illumination gained by width of beam 28 when compared to laser beam 34 (Figure 3) compensates for the lesser intensity of beam 28, allowing for effective threat neutralization. Further, since the reaction time to a detected threat is low (less than 100 ms), aircraft survivability is increased. In addition the removal of a dedicated tracking system allows for a significantly less expensive and more robust system.

Depicted in Figure 5 and Figures 6A and 6B are two embodiments of an additional DIRCM system developed by Rafael (Israel) and fully described in copending Israeli patent application Nr. 145730.

In Figure 5, small aircraft 10 is provided with an MWS system including detectors 20 and MWS control system 22. Further, small aircraft 10 is provided with a DIRCM system including DIRCM control system 24, dedicated missile tracking system 4 151672/2 26, and a narrow beam broad-band light source (e.g. Xenon lamp) 38. When MWS detectors 20 detect a missile launch, MWS control system 22 evaluates if the launched missile is a threat 18. If the missile is a threat, MWS control system 22 hands-off the trajectory of threat 18 to DIRCM control system 24, which aims light source 38 at threat 18 to illuminate threat 18 with narrow light-beam 40. Dedicated missile tracking system 26 tracks threat 18 and ensures that threat 18 remains illuminated by beam 40 by directing light source 38, until threat 18 is no longer a threat to small aircraft 10. Beam 40 produced by light source 38 is relatively narrow, being no more than approximately 4°, and preferably much narrower, e.g. 0.5" as depicted in Figure 5.

Figures 6A and 6B illustrate a second embodiment of the DIRCM system described in copending Israeli patent application Nr. 145730. In Figures 6A and 6B, small aircraft 10 is provided with an MWS system including detectors 20 and MWS control system 22. Further, small aircraft 10 is provided with DIRCM system including DIRCM control system 24, dedicated missile tracking system 26, and variable width beam broadband light source 42. When MWS detectors 20 detect a missile launch, MWS' control system 22 evaluates if the launched missile is a threat 18. When threat 18 is detected, DIRCM control system 24 reacts immediately, commanding light source 42 to illurninate threat 18 using the threat trajectory found by MWS control system 22, Figure 6A. The width of beam 44a used to iUuminate threat 18 is selected such that threat 18 is effectively illuminated despite the relatively inaccurate trajectory detected by MWS control system 22. Thus, width of beam 44a is relatively broad, e.g. 4° or more. If the accuracy of the threat trajectory found by the MWS is sufficient, the beam width can be reduced. Simultaneously, with the engagement of threat 18 by beam 44a, MWS control system 22 hands-off the trajectory of threat 18 to DIRCM control system 24 that activates dedicated missile tracking system 26. Once dedicated missile tracking system 26 acquires threat 18, DIRCM control system 24 causes light source 42 to produce narrower light beam 44b, for example, of no more than approximately 1 ° wide, or even less than 0.25°, as depicted in Figure 6B. Since dedicated missile tracking system 26 can identify the trajectory of threat 18 much more accurately then MWS control system 22, light beam 44b is much narrower than light beam 44a to increase the energy density illuminating threat 18, and consequently the neutralization efficiency.

The DIRCM systems known in the art, especially those produced by Rafael, are highly effective in defending certain types of aircraft. Aircraft with a small thermal signature or fast and agile aircraft equipped with the prior art DIRCM systems have a relatively high survivability when challenged by an infrared-guided threat.

In recent years the need to defend other aircraft, especially large civilian or military passenger transports has increased. Relatively cheap shoulder-fired missiles are becoming increasingly available to militants who may target a passenger aircraft to further political ends. Unfortunately, prior art lamp-based DIRCM systems are insufficient to defend large passenger transport aircraft from such missiles. Passenger aircraft are slow and virtually non-maneuverable, especially during the take-off and landing stages of flight. In addition, as these are multi-engine aircraft designed for efficient peacetime flight, the thermal signature of these aircraft is very large. The illumination power deployed and engagement time available for prior art lamp-based DIRCM systems to neutralize a thermal-guided threat is insufficient to effectively protect this type of aircraft. Lamps that are suitable and sufficiently powerful are unavailable. The illumination power available to laser-based DIRCM systems may suffice. However laser-based DIRCM systems are generally expensive and not robust as the dedicated missile tracking system must be exceptionally accurate and mechanical components of the gimbal-mount need to have an exceptional high tolerance and tracking accuracy.

There is a need for a lamp-based DIRCM system able to deploy significantly greater illumination power then known in the art in order to neutralize a infrared-guided threat to an aircraft with a large thermal signature. Such a system must be relatively cheap to allow acceptance in the civilian aircraft market. In addition, such a DIRCM system must be easily attached to existing aircraft with little modification when the aircraft must fly in high-risk airspace. The system must also be easily detachable when the aircraft is to fly in low-risk airspace in order to lower fuel costs and increase cargo capacity. Such a system is preferably simple to operate with little training required.

SUMMARY OF THE INVENTION There is provided according to the teachings of the present invention a DIRCM system, useful for defeating a threat posed by a thermal-guided threat made up of: (a) a missile warning system (MWS); (b) a DIRCM control system; (c) two or more individual non-laser light sources (e.g. arc lamps such as Xenon lamps) and (d) a trigger, configured to synchronize activation and deactivation of the individual light sources to within 1 millisecond, preferably to within 1 microsecond.

According to a further feature of the present invention, the individual light sources are mounted on the same gimbal. According to an additional feature the individual light sources are mounted coaxially to each other. 7 151672/2 According to a further feature of the present invention, the angular width of each one the individual light sources is greater than 0.01 °.

According to a feature of the present invention, the DIRCM system also includes (e) a dedicated missile tracking system separate from the MWS. Components of the dedicated missile tracking system, such as the threat sensors, are preferably mounted on the same gimbal as the light sources.

According to a further feature of the present invention, the components of the DIRCM system are deployed in one or more separate packages (e.g. pods or nacelles) configured to be easily attachable to and detachable from an aircraft, for example to hard points on the wings or aircraft underbelly. When deployed in separate packages, it is possible that the DIRCM system receives necessary power from the aircraft itself, or, according to a feature of the present invention, the separate packages are equipped with an autonomous power supply (for example, batteries, fuel cells, generators).

According to a further feature of the present invention, the DIRCM system is configured to operate autonomously with substantially little pilot intervention. For example, the pilot can simply activate / inactivate the DIRCM system and initiate a self-test According to a still further feature, the DIRCM system of the present invention is configured to be automatically activated when the aircraft is at risk (based on, for example, altitude, velocity, location or initiation of take-off / landing procedures) and autonomously engage a threat. If the DIRCM system fails a self-test, the pilot is then warned and is then able to contact technical personnel.

According to a further feature of the present invention, at least some of the communication between components of the DIRCM system of the present invention is wireless. 8 151672/2 There is also provided according to the teachings of the present invention a method for neutralizing the threat posed by a guided missile by (a) detecting the guided missile; (b) detecting the trajectory of the guided missile; and c) illuminating the guided missile with light from two or more of individual light sources, simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, where: FIG. 1 (prior art) is a schematic depiction of a permanently lit wide illumination DIRCM system; FIG. 2 (prior art) is a schematic depiction of a DIRCM system using a gimbal-mounted lamp and a dedicated missile tracking system; FIG. 3 (prior art) is a schematic depiction of a DIRCM system using a gimbal-mounted laser and a dedicated missile tracking system; FIG. 4 (prior art) is a schematic depiction of a DIRCM system using a gimbal-mounted lamp and the MWS to direct the light beam; FIG. 5 (prior art) is a schematic depiction of a DIRCM system using a gimbal-mounted narrow beam lamp and a dedicated missile tracking system; FIGS. 6A and 6B (prior art) is a schematic depiction of a DIRCM system using a gimbal-mounted variable width beam and a dedicated missile tracking system; FIGS 1 to 6B have been described hereinabove; FIGS. 7A and 7B are schematic depictions of light sources useful in a DIRCM system of the present invention; FIG. 8 is a schematic depiction1 of an embodiment of the DIRCM system of the present invention using six individual gimbal-mounted lamps mounted in an underbelly nacelle; FIG. 9 is a schematic depiction of an embodiment of the DIRCM system of the present invention using four individual gimbal-mounted lamps and a dedicated missile tracking system mounted in an underbelly nacelle; FIGS. 10A and 10B are a schematic depiction of an embodiment of the DIRCM system of the present invention using four individual variable beam-width gimbal-mounted lamps and a dedicated missile tracking system mounted in an underbelly nacelle; and FIG. 1 1 is a schematic depiction of an embodiment of the DIRCM system of the present invention where the components of the DIRCM system are mounted in an aircraft-attachable pod and control of the DIRCM system is performed using wireless communications.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is of a DIRCM system that is effective in neutralizing an infrared-guided threat to a non-agile and high thermal signature aircraft, such as a commercial passenger aircraft yet is cheap and easy to operate. The DIRCM system of the present invention simultaneously illuminates a threat with two or more individual non-laser light sources so that the illumination power density is sufficient to neutralize the threat. 151672/2 The principles and operation of a DIRCM system according to the present invention may be better understood with reference to the drawings and the accompanying description.

The basic principle of the present invention is to provide a method and a device to illuminate the seeker of a threat with sufficient energy to neutralize the threat without using a laser and overcoming the fact that no single appropriate light-source currently available is sufficiently intense. The approach to solving this problem is by providing two or more non-laser light sources to simultaneously illuminate the threat. Two major problems must be overcome. The first is that all of the light sources must be synchronized to turn on and to turn off within less than a millisecond of each other and preferably within less than a microsecond of each other. The second is that all of the light sources must all be directed at the seeker of the threat.

Once these two problems are solved, a sufficient number of individual light sources are provided to neutralize a threat The exact number of individual light sources necessary is dependent on the size of the thermal signature of the protected target, the engagement range countenanced and the nature of the threat. The number of light sources necessary is easily calculated by one skilled in the art. A type of device able to overcome the two problems is schematically depicted in Figures 7 A and 7B.

In Figure 7A, a preferred embodiment of a lamp assembly 46 of the present invention is depicted. Inside a turret 48 is contained a gimbal mount 50. Rigidly and coaxially mounted in gimbal mount 50 are six individual light sources 52a, 52b, 52c, 52d, 52e and 52f. Each one of light sources 52a to 52f has a lens diameter of roughly 5 cm. Supplying power to light sources 52a to 52f is a pulser 54. 151672/2 When necessary, pulser 54 triggers light sources 52a to 52f to produce respective light beams 56a, 56b, 56c, 56d, 56e and 56f. As is clear to one skilled in the art, despite the fact that light sources 52a to 52f are coaxial, due to the finite angular width of beams 56a to 56f, at some distance beams 56a to 56f effectively overlap to produce a single composite beam of light. The distance from which light beams 56a to 56f produced by light sources 52a to 52f arrayed in a coaxial hexagonal arrangement as in lamp assembly 46 produce a composite light beam of at least 5 cm width as a function of the angular width of beams 56a to 56f is listed in Table 1.

TABLE 1. Distance for production of 5 cm composite, beam for lamp assembly 46 angular width (degrees) distance (meters) 0.0191 300 0.25 22.9 2.0 2.9 4.0 1.4 In Figure 7B, a lamp assembly 58, related to lamp assembly 46 of Figure 7A is depicted. Lamp assembly 58 is equipped with four light sources, 52a, 52b, 52c and 52d, and with an optical device 60, separated from light sources 52a to 52d by' a non- transparent partition 62. Partition 62 prevents blinding of optical device 60 by light sources 52a to 52d. Optical device 60 is a sensor of dedicated missile tracking system 26, dedicated to the actual tracking of a threat. Supplying power to light sources 52a to 52d is a pulser 54.

When necessary, pulser 54 triggers light sources 52a, 52b, 52c and 52d to produce light beams 56a, 56b, 56c and 56d, respectively. As is clear to one skilled in the art, despite the fact that light sources 52a to 52d are coaxial, due to the finite angular width of beams 56a to 56d, at some distance beams 56a to 56d effectively overlap to produce a single composite beam of light The distance from which light beams produced by light 12 151672/2 sources 52a to 52d arrayed in a coaxial square arrangement in lamp assembly 58 produce a composite beam of at least 5 cm width as a function of the angular width of beams 56a to 56d is listed in Table 2.

TABLE 2. Distance for production of 5 cm composite beam for lamp assembly 58 angular width (degrees) distance (meters) 0.0135 3 0.25 16.2 0.5 8.1 1 4.0 2 2.0 4 1.0 As is clear to one skilled in the art, for two or more individual light sources to effectively illuminate a single threat within the context of a DIRCM system, the iUumination of all the light sources must be synchronized to better than millisecond accuracy, preferably to better than microsecond accuracy and even more preferably to nanosecond accuracy. "Pulsers" (high voltage pulsed power supplies) are devices known to one skilled in the art that can be used to synchronize light source activation and deactivation in a fashion suitable for use in the present invention. For example, pulsers based on cascaded field effect transistors (FET) which can be synchronized to the order of nanoseconds are commercially available, for example, from Kentech Instruments Ltd., (Oxfordshire, United Kingdom). Such pulsers can be used to synchronize the plurality of light sources of the DIRCM system of the present invention.

Depending on the details of the DIRCM system, the angular beam widths of light sources 52a to 52d as well as the method of use of the DIRCM system itself are determined.

Figure 8 is a schematic depiction of an aircraft 64 equipped with a first embodiment of the DIRCM system of the present invention, confined within a nacelle 13 151672/2 66 attached to the underbelly of aircraft 64. When MWS detectors 20 and MWS control system 22 identify threat 18, the threat trajectory calculated by the MWS control system 22 is used by DIRCM control system 24 to direct a lamp assembly 46, similar to that depicted in Figure 7 A, to illurninate threat 18 with composite beam 70. Composite beam 70 is composed of six separate relatively wide (e.g., 4") beams such as beams 56a to 56f in Figure 7A. As a result, the angular width of composite beam 70 is 4" and already at a distance of 1.4 meters (see Table 1) is large enough to be effectively illurninate threat 18, in analogy to the DIRCM system depicted in Figure 4. The advantages of a DIRCM system as depicted in Figure 8 is the speed of reaction as no hand-off time is required and the fact that the lack of a dedicated tracking system allows for a much less expensive and more robust system. The fact that threat 18 is simultaneously iUuminated by more than one lamp (in lamp assembly 46 there are six light sources 52a to 52f) means that enough illumination power density is available to neutralize threat 18.

Figure 9 is a schematic depiction of an aircraft 64 equipped with a second embodiment of the DIRCM system of the present invention, confined within a riacelle 66 attached to the underbelly of aircraft 64. The second embodiment of the DIRCM system of the present invention includes a dedicated missile tracking system 26, which allows for accurate aiming of a gimbaled lamp assembly 58 to illuminate threat 18 with a narrow compositelight beam 72 (e.g., 0.5° in Figure 9). Gimbaled lamp assembly 58 in Figure 9 is similar to gimbaled lamp assembly 58 depicted in Figure 7B.

When MWS detectors 20 detect a missile launch, MWS control system 22 evaluates if the launched missile is a threat 18. If the missile is a threat, MWS control system 22 hands-off the trajectory of threat 18 to DIRCM control system 24. DIRCM control system 24 activates dedicated missile tracking system 26 (of which optical 14 151672/2 device 60 is a component) to detect the trajectory of threat 18 with relatively high accuracy. Using the accurate trajectory of threat 18, DIRCM control system 24 directs narrow composite light beam 72 to illuminate threat 18. Dedicated missile tracking system 26 continuously tracks threat 18, ensuring that threat 18 remains illuminated by composite beam 72 until threat 18 is no longer a threat to aircraft 64.

Composite beam 72 is composed of four separate relatively narrow beams such as beams 56a to 56d in Figure 7B, being no more than approximately 4°, preferably less than 2°, more preferably less than Γ, even more preferably less than 0.5°, and most preferably less than 0.25°. As a result, the angular width of composite beam 72 is less than 4°, less than 2°, less than Γ, less than 0.5° and less than 0.25°, respectively. From Table 2 is seen that composite beam 72 is large enough to be effectively illuminate threat 18, already at distances of 1, 2, 4, 8 and 16 meters respectively, in analogy to the DIRCM system depicted in Figure 5.

Dedicated missile tracking system 26 of Figure 9 (and Figure 5) must detect a trajectory of threat 18 in order to aim composite beam 72 with a few tenths of a' degree width as opposed to a 3 microradian (-0.005*') wide laser beam 34 of the DIRCM system depicted in Figure 3. The DIRCM system depicted in Figure 9 is simple and robust relative to dedicated tracking system 26 depicted in Figure 3. The fact that threat 18 is simultaneously illuminated by more than one lamp (in Figure 9, four light sources 52a to 52d) means that enough illumination power density is available to neutralize threat 18.

Figures 10A and 10B illustrate a third embodiment of the DIRCM system of the present invention confined within a nacelle 66 on the underbelly of aircraft 64. The third embodiment of the DIRCM system of the present invention includes a dedicated missile tracking system 26 which allows for accurate aiming of composite beam 76b (Figure 10B) 151672/2 produced by gimbaled lamp assembly 74. Gimbaled lamp assembly 74 in Figures 10A and 10B is similar to gimbaled lamp assembly 58 depicted in Figure 7B except that gimbaled lamp assembly 74 is provided with four variable beam-width light sources.

In Figure 10A, when MWS detectors 20 detect a missile launch, MWS control system 22 evaluates if the launched missile is a threat 18. When threat 18 is detected, DIRCM control system 24 reacts immediately (less than 100 ms), directing the variable beam- width light sources of gimbaled lamp assembly 74 to illuminate threat 18 using the threat trajectory found by MWS control system 22, Figure 10A. The width of composite beam 76a used to illuminate threat 18 is selected such that threat 18 is effectively illuminated despite the relatively inaccurate trajectory detected by MWS control system 22. Thus, width of beam 76a is relatively broad, e.g. 4°. If the accuracy of the threat trajectory found by MWS control system 22 is sufficient, the beam width is preferably 2° or greater and more preferably Γ or greater. As in first embodiment of the present invention depicted in Figure 8 there is no hand-off delay and threat 18 is immediately engaged.

Simultaneously with the engagement of threat 18 by composite beam 76a, DIRCM control system 24 activates dedicated missile tracking system 26 of which optical device 60 is a component. Once dedicated missile tracking system 26 acquires an accurate trajectory of threat 18, DIRCM control system 24 aims gimbaled lamp assembly 74 based on the accurate trajectory found by dedicated missile tracking system 26. DIRCM control system 26 causes the variable beam-width light sources of gimbaled lamp assembly 74 to produce narrow composite light beam 76b of Figure 10B for example, with a width of no more than approximately wide, preferably no more than 0.5° wide and even more preferably less then 0.25' as depicted in Figure 10B. Since dedicated missile 16 151672/2 tracking system 26 can identify the trajectory of threat 18 much more accurately then MWS control system 22, compositelight beam 76b is much narrower in order to increase the energy density illuminating threat 18, and consequently threat neutralization efficiency.

As is clear to one skilled in the art, the relative width of compositelight beam 76a and 76b is ultimately determined by the accuracy of the trajectories determined by the MWS control system 22 and dedicated missile tracking system 26, respectively. For example, if MWS control system 22 is configured to determine a trajectory as accurately as in the DIRCM system of Figure 4, then the width of composite light beam 76a is approximately 4°. If the trajectory determined by dedicated missile tracking system 26 is sixteen times more accurate, then the width of composite light beam 76b is approximately Γ.

Production of a light source, such as a Xenon lamp, with a variable beam width in the order of from about 4° to down about 0.5° is known to one skilled in the art by use, for example, of variable geometry reflectors or variable focal length lenses. Means necessary for making variable beam width lamps are commercially available, for example from Ballantyne of Omaha, Inc., (Omaha, Nebraska, U.S.A.).

The embodiments of the present invention described hereinabove and depicted in Figures 7A, 7B, 8, 9, 10A and 10B have four or six individual light sources. It is clear to one skilled in the art that the number of light sources provided is determined on a case by case basis to ensure neutralization of the expected threats. Operation and design of a system of the present invention with more or less individual light sources is, in analogy to the embodiments explicitly described hereinabove, clear to one skilled in the art The purpose of the DI RCM system of the present invention is to defend large passenger aircraft from thermal-guided threats. Clearly the lion's share of such aircraft do not need to be defended from thermal-guided threats, making it undesirable that the DIRCM system of the present invention be fully integrated into the aircraft during production. Thus it is exceptionally preferable that the DIRCM system of the present invention be easily attachable and detachable to an aircraft. Further, since the DIRCM system is not a permanent fixture of an aircraft, the DIRCM system of the present invention is preferably operable without necessitating extensive pilot training.

The convenient attachment of peripheral, auxiliary or extra equipment to an aircraft by the use of nacelles or pods attached to the wings or hulls of aircraft is well known in the art. Such nacelles or pods are used to equip an airplane with, amongst others, fuel, armaments, flares and electronic warfare equipment. Most modern aircraft are constructed with strong points at appropriate places for the attachment of nacelles or pods. For example, most large transport aircraft are equipped with at least one strong point on each wing for the purpose of attaching an extra motor. These points are suitable for the attachment of pods or nacelles As is clear to one skilled in the art, the specific details of any nacelle or pod deploying the DIRCM system or components of the system of the present invention are determined by the parameters of the aircraft to be protected. For explanatory purposes, a non-limiting embodiment of a DIRCM system of the present invention is schematically depicted in Figure 1 1.

A DIRCM system of the present invention, provided in an attachable pod 78, is depicted in Figure 1 1. Pod 78 contains MWS detectors 20, MWS control system 22, DIRCM control system 24, elements of dedicated missile tracking system 26 and pulser 54. Pod 78 is also equipped with a lamp assembly 58, analogous to lamp assembly 58 depicted in Figure 7B. Lamp assembly 58 is equipped with four light sources 52 optically separated from optical device 60 by partition 62. Partition 62 prevents blinding of optical device 60 by light sources 52. Optical device 60 is functionally associated with dedicated missile tracking system 26. Pulser 54 is configured to trigger synchronized operation of light sources 52.

As is clear to one skilled in the art, pod 78 require electrical power to operate. Pod 78 can optionally be equipped with an electrical connector to draw electrical power from the aircraft to which pod 78 is attached. It is clear to one skilled in the art, however, that there are many factors that make it preferable that a DIRCM system of the present invention provided in a detachable pod such as pod 78 have an autonomous power supply.

There are many methods to supply the power necessary for operation of the DIRCM system of the present invention, including for example fuel cells, power packs, capacitors, batteries and generators. Since it is expected that most often the DIRCM system of the present invention is operational for only short times during a single flight (e.g. during take-off and landing) the capacity and physical size of an autonomous power supply can be modest. In Figure 1 1, pod 78 is equipped with an auxiliary power unit 80. Auxiliary power units are compact and efficient turbine generators that are well known in the field of aviation and commercially available in many sizes, for example from Hamilton Sundstrand (Windsor Locks, Connecticut, U.S.A.). Fuel 82 for operation of auxiliary power unit 80 is available in pod 78.

The DIRCM system depicted in Figure 1 1 is configured for ease of use. Therefore, the only user-control present is a remote control unit 84 configured for 19 151672/2 wireless communication with DIRCM control system 24 in pod 78 through a transceiver 86. Remote control unit 84 is configured to allow two way communications with DIRCM control system 24 and includes only three buttons. The three buttons are: button 88 "ON" to activate the DIRCM system when the pilot believes a threat exists; button 90 "OFF" to deactivate the DIRCM system when necessary; and button 92 "TEST" to initiate a self-test so that the pilot can be assured that the DIRCM system is properly functioning. A light 94 is illuminated by signals transmitted by transceiver 86 of pod 78 when the DIRCM system is activated.

The DIRCM system depicted in Figure 11 is simple to use. Pod 78 is attached to an aircraft that is to fly to a dangerous airfield. Depending on aircraft parameters and the number of strong points, a plurality of pods 78 can also be attached. The pilot is supplied with a remote control unit 84 for each pod attached (although one remote control unit 84 may be configured to communicate with a plurality of pods 78). A few rninutes before landing, and when well outside the range of an expected threat, the pilot uses remote control unit 84 to activate the DIRCM system. Auxiliary power units 80 are turned on and MWS detectors 20 seek a threat. If a threat is detected, the threat is engaged substantially as described hereinabove.

An even more autonomous system than that depicted in Figure 11 is countenanced. A DIRCM system can be configured to autonomously activate itself with no operator intervention. The DIRCM system when installed monitors data from systems such as an altimeter, a flight speed indicator, flight control systems or a GPS location device to self-activate in high risk situations. Only upon a failure of a self-test is the pilot warned. The pilot then contacts technical personnel.

While the invention lias been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. For example, although described as being useful against infrared guided missiles, with appropriate modification, the DIRCM system of the present invention can be used against threats guided by radiation at other frequencies (e.g. UV/VIS).

It is clear to one skilled in the art that the system of the present invention can be used to neutralize munitions that are a threat to an entity that is not the platform on which the system of the present invention is deployed. For example, a DIRCM system of the present invention may be located at a ground station for example at the periphery of a threatened airfield. A special DIRCM aircraft (manned aircraft, unmanned aircraft, blimp, zeppelin) equipped with the DIRCM system of the present invention may be deployed in the vicinity of a high risk airfield. This is useful to allow large supply aircraft to land at the airfield even before the airfield is completely secured, for example in the framework of a rapid deployment force. Thus, it is understood that the specification and examples are illustrative and do not limit the present invention. Other embodiments and variations not described herein understood to be within the scope and spirit of the invention.

Claims (30)

1. 51672/4 1 A system for illuminating and thereby defeating an infrared guided threat to an aircraft comprising: a) at least two non-laser light sources; b) a trigger configured to activate said at least two non-laser light sources to generate at least two light beams, said light beams overlapping to produce a composite beam of enough illumination power density to jam or destroy an infrared seeker of the infrared guided threat; and c) a DIRCM control system, configured to aim said composite beam at the infrared guided threat, thereby illuminating the infrared guided threat with said composite beam thereby jamming or destroying said infrared seeker.

2. The system of claim 1, further comprising: d) a missile warning system configured to supply said DIRCM control system with a first trajectory of the infrared guided threat , said aiming being according to said first trajectory.

3. The system of claim 1, further comprising: d) a dedicated missile tracking system configured to supply said DIRCM control system with a second trajectory of the infrared guided threat , said DIRCM control system configured to aim said composite beam accurately at the infrared guided threat according to said second trajectory.

4. The system of claim 3, further comprising e) a gimbal, and wherein a component of said dedicated missile tracking system 151672/4 22 is mounted on said gimbal.

5. The system of claim 1 , wherein said trigger is a pulser.

6. The system of claim 1, further comprising d) a gimbal, and wherein said at least two light sources are mounted on said gimbal.

7. The system of claim 6, wherein said at least two light sources are mounted on a single gimbal.

8. The system of claim 7, wherein said at least two light sources are mounted coaxially on said single gimbal.

9. The system of claim 1, wherein each of said at least two light beams has an angular width greater than 0.0 .

10. The system of claim 1, further comprising: d) a mechanism for varying a beam width of at least one of said at least two light beams; and wherein said DIRCM control system is further configured to control said mechanism for varying said beam width.

11. The system of claim 1, wherein said at least two light sources are arc lamps.

12. The system of claim 11, wherein said arc lamps are Xenon lamps.

13. The system of claim 1, wherein at least some components of the system are deployed separate from the aircraft. 151672/4 23

14. The system of claim 1, further comprising: d) a package for deploying at least one component selected from the group consisting of said at least two lights, said DIRCM control system, a MWS control system, an optical device, a detector, said trigger, a dedicated missile tracking system and a transceiver wherein said package is reversibly attached to the aircraft.

15. The system of claim 14, wherein said package is a nacelle.

16. The system of claim 14, wherein said package is a pod.

17. The system of claim 14, wherein said package receives power from the aircraft.

18. The system of claim 14, further comprising: e) an autonomous power supply, said autonomous power supply for supplying power to said package and said autonomous power supply being deployed on said package.

19. The system of claim 1, further comprising: d) a remote control, said remote control configured to activate at least one component selected from the group consisting of said DIRCM control system, a MWS control system, an optical device, a detector, a dedicated missile tracking system and a power supply.

20. The system of claim 1, wherein wireless communication is used to transfer information between at least two components selected from the group consisting of said DIRCM control system, a MWS control system, an optical device, a detector, a dedicated missile tracking system, a remote control unit and a power supply.

21. The system of claim 1, wherein said DIRCM control system is further configured to be activated autonomously.

22. The system of claim 1, wherein said trigger is configured to synchronize activation of said at least two light sources to within less than 1 microsecond.

23. The system of claim 22, wherein said trigger is configured to synchronize activation of said at least two light sources to within less than 1 nanosecond.

24. A method for illuminating and thereby defeating an infrared guided threat to an aircraft comprising the steps of: a) detecting the infrared guided threat; b) activating at least two non-laser light sources to produce a composite beam, said composite beam having enough illumination power density to jam or destroy an infrared seeker of the infrared guided threat; and c) illuminating the infrared guided threat with said composite beam thereby jamming or destroying said infrared seeker.

25. The method of claim 24, wherein said activating is performed by a pulser.

26. The method of claim 24, wherein activation of a first non-laser light source of said at least two non-laser light sources is synchronized to activation of a second non-laser light source of said at least two non-laser light sources to within less than 1 millisecond. 151672 25

27. The method of claim 26, wherein activation of a first non-laser light source of said at least two non-laser light sources is synchronized to activation of a second nonlaser light source of said at least two non-laser light sources to within less than 1 microsecond.

28. The method of claim 27, wherein activation of a first non-laser light source of said at least two non-laser light sources is synchronized to activation of a second non-laser light source of said at least two light sources to within less than 1 nanosecond.

29. The method of claim 24, wherein each light beam of said at least two light beams has an angular width greater than 0.01°.

30. The method of claim 24, wherein said at least two light sources are mounted coaxially.