ACTIVE PROTECTION METHOD AND SYSTEM

Information

  • Patent Application
  • 20100026554
  • Publication Number
    20100026554
  • Date Filed
    September 20, 2007
    16 years ago
  • Date Published
    February 04, 2010
    14 years ago
Abstract
There is provided an active protection system and an active protection method preferably for airborne platforms. According to the embodiment of the invention, the active protection system is mounted onboard a platform for protecting the platform, and comprises a radar system configured for generating output data including threat output data corresponding to a velocity, a range, and an angle of the threat with respect to the platform in an airspace around the platform, the output data being useful for detecting, identifying and tracking of at least one threat approaching the platform; a countermeasure system capable of launching at least one non-fragmentation interceptor projectile in response to receiving a control command; and a control unit configured for receiving the output data from the radar system and for generating the control command and transmitting the control command to the at least one non-fragmentation interceptor projectile, thereby enabling countering the threat.
Description
FIELD OF THE INVENTION

This invention relates to an active protection method and system and more specifically to active protection method and system for providing protection from a threat, particularly for use with a mobile or aerial platform such as a helicopter, UAV (Unmanned Aerial Vehicle) or the like.


BACKGROUND OF THE INVENTION

A variety of methods are known relating to protecting a vehicle or the like from a destructive threat.


For example, U.S. Pat. No. 4,233,605 discloses a Doppler radar signature simulator decoy for protecting a helicopter under attack by hostile weapons which home in on a Doppler radar return signal from the helicopter rotors. The decoy returns a strong radar signal which duplicates a relatively weaker signal emitted from the helicopter rotors, leading hostile weapons to the decoy.


U.S. Pat. No. 6,980,151 discloses a bi-static continuous wave radar system and related methods for detecting incoming threats from ballistic projectiles includes a remote source of RF illumination, and a local receiver installed in one or more target aircraft. A first receiving channel acquires direct path illumination from the source and provides a reference signal, and a second receiving channel acquires a scatter signal reflected by a projectile. A processor coupled to each receiver corrects scatter signal Doppler offset induced by relative source motion, isolates narrowband Doppler signals to derive signatures characteristic of the projectile, and by executing appropriate algorithms, compares the derived signatures to modeled signatures stored in memory. If the comparison yields a substantial similarity, the processor outputs a warning signal sufficient to initiate defensive countermeasures.


U.S. Pat. No. 7,066,427 discloses an interceptor device adapted to protect a platform associated therewith against an incoming threat having a trajectory by intercepting the threat in an intercept zone. Such an interceptor device comprises a housing defining an axis and a countermeasure device operably engaged with the housing. At least one detonating charge is housed by the housing and is operably engaged with the countermeasure device. A controller device is in communication with the at least one detonating charge, wherein the controller device is housed by the housing and is configured to direct the at least one detonating charge to deploy the countermeasure device at least partially radially outward with respect to the axis of the housing and in correspondence with the trajectory of the threat to thereby cause the countermeasure to impact the threat in the intercept zone.


One active protection defense system is the Flight Guard™ system available by Israel Aircraft Industries™ Ltd. and Elta Systems™ Ltd., Israel. The Flight Guard™ system is mounted onboard an airborne platform, and is designed to detect an approaching heat seeking threat and in response, launch a deceiving countermeasure (flares). (The Flight Guard™ system is described e.g. at www.israeli-weapons.com/weapons/aircraft/systems/flight_guard/Flight_Guard.htm).


Another active protection defense system is the Trophy™ system marketed by General Dynamics™, USA and designed by a consortium comprising Rafael Armament Development Authority Ltd., Israel Aircraft Industries™ Ltd., Elta Systems™ Ltd and Israel Military Industries™ Ltd., Israel. The Trophy™ system creates a hemispheric protected zone around the vehicle where incoming threats are intercepted and defeated. It has three elements providing threat detection and tracking, launching and intercept functions. The threat detection and warning subsystem consists of several sensors, including flat-panel radars, placed at strategic locations around the protected vehicle, to provide full hemispherical coverage. Once an incoming threat is detected, identified and verified, a countermeasure assembly is opened, and a countermeasure device is positioned in the direction where it can effectively intercept the threat. Then it is launched automatically into a ballistic trajectory to intercept the incoming threat at a relatively long distance (The Trophy™ system is described e.g. at www.defense-update.com/products/t/trophy.htm and www.defensereview.com/modules.php?name=News&file=print&&sid=861).


The following publications are also of interest: U.S. Pat. Nos. 7,059,567 and 5,661,254; US Patent application No. 2006/0103569.


RPG's (Rocket Propelled Grenade) represent a serious threat to mobile land and aerial platforms. RPG's are considered the second cause of death of US soldiers in the Iraq war. According to certain assessments, inexperienced RPG operators could engage a stationary target effectively from 150-300 meters, while experienced users could kill a target at up to 500 meters, and moving targets at 300 meters. One known way of protecting a platform against RPG's is to cause explosion or discharge of the RPG's warhead away from the platform. Another known protection approach against RPG's and short range missiles employ fitting the platform to be protected with armor (e.g. reactive armor, hybrid armor or slat armor).


There is a need in the art for an improved protection system for providing protection for mobile or aerial platforms, such as a helicopter or the like, from a projectile threat. There is a need in the art for a protection system for protection against projectile threats, such as RPG's (Rocket Propelled Grenade), short range missiles or rockets and similar threats. There is also a need in the art for a protection system having relatively very short reaction time. There is a further need in the art for a protection system for protection against projectile threats, being relatively light weighted and suitable to be mounted onboard mobile and aerial platforms.


SUMMARY OF THE INVENTION

Herein, “aerial threat” or “airborne threat” or “threat” are used interchangeably to refer to any threat, including projectiles, rockets, missiles and other aerial weapons, having a trajectory and ordnance such that may cause damage to a body or location that it is desired to protect if allowed to intercept and/or detonate and/or impact said body or location.


The protection systems and methods of the invention are useful for protecting many kinds of aerial platforms, including but not limited to, helicopters, UAV's (Unmanned Airborne Vehicle), RPV's (Remotely Piloted Vehicle), light aircraft, hovering platforms, low speed traveling platforms. The protection systems and methods of the invention are useful for protecting platforms against many kinds of threats, including but not limited to, guided missiles or rockets, unguided missiles or rockets, self-guided and maneuvering missile or rocket, heat seeking missiles or rockets, radar lock missiles or rockets, shoulder missiles or rockets, short range missiles or rockets, RPG (Rocket Propelled Grenade), TOW (Tube-launched, Optically tracked, Wire-guided missile), Hot, Milan, Cornet, Stinger, Strela, and Sager.


The invention can be used with many types and kinds of countermeasure projectiles, including, but not limited to, non-guided rocket or missile; guided rocket or missile; and self-guided and maneuvering rocket or missile. According to an aspect of the invention there is provided an active protection system mountable onboard a platform for protecting the platform, comprising:


a radar system configured for generating output data including threat output data corresponding to a velocity, a range, and an angle of the threat with respect to the platform in an airspace around the platform, the output data being useful for detecting, identifying and tracking of at least one threat approaching the platform, and;


a countermeasure system capable of launching at least one non-fragmentation interceptor projectile in response to receiving a control command;


a control unit configured for receiving the output data from the radar system and for generating the control command and transmitting the control command to the at least one non-fragmentation interceptor projectile, thereby enabling countering the threat


According to an embodiment of the invention, the radar system comprising one or more sensor unit, located at selected locations onboard the platform. According to another embodiment, the radar system is further configured for tracking of the at least one projectile, and generating output data corresponding to a velocity, a range and an angle of the projectile with respect to the platform. According to an embodiment of the invention, the radar system is a multibeam radar, a digital multibeam radar or a phased-array radar, e.g. a 32-beam multi-beam radar system or a digital multi beam radar system. For example, the radar system is designed to operate in a 10-20 GHz frequency range, and the weight of the radar system is in the range of 10-100 Kg.


According to an embodiment of the invention, the countermeasure system comprises one or more recoilless battery of projectiles, located at selected locations onboard the platform, and associated with at least one activation unit, the activation unit being operatively connected to the control unit and configured for responding to a command signal from the control unit by launching one or more projectiles. According to another embodiment of the invention, the countermeasure system comprises at least one recoilless battery of projectiles, associated with at least one activation and aiming unit, the activation and aiming unit being operatively connected to the control unit and configured for responding to a command signal from the control unit by aiming and launching one or more projectiles. Aiming is performed by aiming the battery as a whole or by aiming at least one part thereof.


According to certain embodiments of the invention, in the case where guided projectiles are used, the system further comprises a guidance system capable of guiding the projectile toward an engagement with the threat. According to other embodiments of the invention, the system further comprises communication unit operable to facilitate at least uplink communication with the projectile, thereby enabling guiding the projectile toward a predicted engagement point with the threat.


According to an embodiment of the invention, the control unit is a hardware/software utility configured for performing the following operations:

    • (a) detecting, identification and tracking the threat based on processing of the output data;
    • (b) calculating at least trajectory of the threat and the platform and determining an engagement point between the threat and the projectile;
    • (c) determining at least one suitable projectile to be launched, if at all, and generating fire control command; and
    • (d) repeating any of operations (a) to (c) as many times as required.


According to another embodiment of the invention, the control unit is a hardware/software utility configured for performing the following operations:

    • (a) detecting, identification and tracking the threat based on processing of the output data;
    • (b) calculating at least trajectory of the threat and the platform and determining an engagement point between the threat and the projectile;
    • (c) determining at least one suitable projectile to be launched and, if at all, and generating aiming and fire control command; and
    • (d) repeating any of operations (a) to (c) as many times as required.


According to certain embodiments of the invention, the control unit is communicatively coupled to platform instrumentation for receiving at least platform trajectory data and the calculation of the trajectory of the threat and the platform is carried out based on platform trajectory data received from the platform instrumentation. According to other embodiments, the control unit is further configured for processing platform trajectory data based on the output data, and the calculation of the trajectory of the threat and the platform is carried out based on the platform trajectory data. According to other embodiments, the control unit is further configured for tracking the at least one projectile, after it was launched, and to perform operations (b) and (c) based on information corresponding to velocity, range and angle of the projectile with respect to the platform that is measured after launch. According to an embodiment of the invention, in case the countermeasure system includes more than one battery of projectiles, each located at different locations onboard the platform, the control unit is further configured for selecting one from among the batteries, in accordance with a predefined criteria, for launching the projectile, and for directing the command signal accordingly.


According to another aspect of the invention there is provided an active protection method for protecting a platform against an approaching threat, comprising:

    • (a) generating radar output data measured by a radar system mounted onboard the platform, including threat output data corresponding to a velocity, a range and an angle of the threat with respect to the platform in an airspace around the platform, and detecting, identifying and tracking of at least one threat approaching the platform based on processing of at least the output data;
    • (b) providing onboard the platform a countermeasure system capable of launching at least one non-fragmentation interceptor projectile in response to receiving a control command;
    • (c) based on at least the output data, generating the control command and transmitting the control command to the at least one non-fragmentation interceptor projectile,


      thereby enabling countering the threat.


According to an embodiment of the invention, the generating of radar output data is carried out based on measurements received from one or more sensor unit, located at selected locations onboard the platform. According to an embodiment of the invention, the method comprises tracking of the at least one projectile, and generating CM output data corresponding to a velocity, a range and an angle of the projectile with respect to the platform. According to an embodiment of the invention, the method comprises providing uplink communication with the projectile, thereby enabling guiding the projectile toward a predicted engagement point with the threat. According to an embodiment of the invention, the method comprises: calculating at least trajectory of the threat and the platform and determining an engagement point between the threat and the projectile; determining at least one suitable projectile to be launched, if at all; and repeating any one of operations (a) to (g) as many times as required. According to an embodiment of the invention, the method comprises tracking the at least one projectile, after it was launched, and performing the calculating operation and/or determining operation based on information corresponding to velocity, range and angle of the projectile with respect to the platform, measured after launch. According to an embodiment of the invention, in case the countermeasure system includes more than one battery of projectiles, each located at different locations onboard the platform, the method comprises selecting one from among the batteries, in accordance with a predefined criteria, for launching the projectile, and directing the command signal accordingly. According to an embodiment of the invention, the method comprises receiving platform trajectory data from platform instrumentation, and the calculation of the trajectory of the threat and the platform is carried out based on platform trajectory data received from the platform instrumentation. According to another embodiment of the invention, platform trajectory data is processed based on radar output data.





BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:



FIG. 1 is a schematic representation of an active protection system according to an embodiment of the invention;



FIG. 2 is a more detailed representation of an active protection system according to an embodiment of the invention; and



FIG. 3 is a flow chart illustrating a sequence of operations carried out in accordance with an embodiment of the invention.





DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an active protection system and method for protecting a platform against aerial threats. In the following, the concept of the invention will be disclosed mainly with reference to the protection of aerial platforms and specifically helicopters (other non-limiting examples of aerial platforms are RPV (Remotely Piloted Vehicle), UAV (Unmanned Airborne Vehicle), light aircraft, hovering platforms, low speed traveling platforms and more), however the invention is not limited thereto. The protection system and method of the invention is useful against a variety of threats, such as RPG's, short range guided and unguided missiles or rockets, heat seeker missiles or rockets, radar lock missiles or rockets, shoulder missiles or rockets, and the like.


As illustrated in FIG. 1, a helicopter 100 is fitted with an active protection system 10 (not shown in its entirety in FIG. 1), for protecting the helicopter 100 against one (or a variety of) RPG threat 120 (only one threat 120 is shown). According to certain embodiments of the invention, the protection system 10 is capable of detecting, identifying and tracking the threat 120, and in response, launching countermeasure devices, e.g. one (or a variety of) projectile 41, and directing it toward threat 120 (only one such projectile is shown). Projectile 41 may be directed or guided toward a desired engagement point EP. According to certain embodiments of the invention, projectile 41 is capable of killing threat 120, e.g. by a direct hit or by discharging the threat (e.g. generating, in proximity to the threat, blast sufficient for harming the threat, such as by discharging of an RPG detonation), substantially without the creation of blast or jet flow that can harm the platform. According to other embodiments of the invention, projectile 41 is aimed at absorbing some or all of the kinetic energy carried by the threat. According to certain embodiments of the invention, the projectile 41 is designed to cause explosion of the threat 120 at a certain safety distance R away from the helicopter (by way of non-limiting example, the engagement between the threat and the projectile is designed to occur at about 30-50 meters away from the helicopter). Thus, risk of damage of the helicopter, or major parts thereof (e.g. propeller) is minimized or eliminated. Safety distance R is selected such that the platform will experience no direct hit from the threat; its particles (in case the threat exploded) or projectile's particles) as well as blast or jet flow. This is different from solutions that allow the platform to be protected to absorb a certain amount of energy, by means of a protecting shield or slat armor mounted thereon.



FIG. 2 is a more detailed illustration of a defense system 40 according to an embodiment of the invention. As shown, the protection system includes a radar system 20, control unit (controller) 30 and countermeasure system 40.


Countermeasure System


According to an embodiment of the invention, countermeasure system 40 comprises at least one battery (or dispenser) of non-fragmentation interceptor projectiles 41. The battery 40 comprises one or a plurality of interceptor projectiles 41 such as guided missiles or rockets, comprised in optionally recoilless launch tubes or ejection racks (not shown). According to an embodiment of the invention, the battery 40 may be placed at a suitable location on the helicopter, and in some embodiments it may be better to have two or more said batteries 40, located at selected locations, for example located on the port side and on the starboard side of the helicopter 100.


Each battery 40 may be associated with an activation unit 42 that is operatively connected to the controller 30, and is configured for responding to a command signal from the controller 30 by launching one or more projectiles 41. For embodiments comprising more than one battery 40 at different locations around the helicopter, the controller may also determine which battery is best located to maximize success of neutralization of the threat, and direct the command signal accordingly. Further, the controller 30 may also determine to launch a projectile 41 from a particular battery 40 as opposed to another battery 40 according to other criteria, for example when the stocks in another battery may be exhausted, and/or when one battery may be much fuller than another, balancing the weight distribution, so long as there is still enough safety margin to destroy the threat safely sufficiently far from the helicopter. Optionally, the controller 30 may provide a command signal for more than one projectile 41 to be launched to counter each moving object 120 of an aerial threat.


Each projectile 41 thus launched can be preprogrammed via the activation unit 42 and with data provided by the controller, to follow a particular desired trajectory designed to intercept the moving objects at a particular, preferably safe distance from the helicopter 100. Alternatively, the desired trajectory for projectile 41 may be provided to the projectile (uplink communication) by means of a closed loop guidance system 50, and a corresponding guidance system comprised in the projectile, enabling the same to be guided to an engagement point via remote control, using positional and trajectory data thereof provided via the radar system 20 and controller 30 to correct the trajectory of the projectile 41 to the desired trajectory.


According to an embodiment of the invention, the location from which a selected projectile would be launched can be determined as follows: the batteries are placed at selected locations onboard the platform, e.g. at the front, back and sides of the platform. During operation, the projectile best suitable for interception is selected and launched at a direction dictated by the position of the platform at the moment of launch. The projectile is directed toward the target (toward the predicted engagement point) during its flight. According to this embodiment, the battery and parts thereof cannot be directed toward a direction required for launch or interception, without maneuvering of the platform as a whole (e.g. preliminary maneuver performed for positioning the platform and hence, one of the batteries, in a suitable launch position). This embodiment employs guided or self-guided (maneuvering) projectiles. Direction of the projectile toward the threat (toward the engagement point) is carried out via uplink communication (as well as downlink communication, according to certain embodiments of the invention), e.g. by providing the projectile with updated threat positioning data (for example, threat coordinates, engagement point coordinates, etc.), or with guidance instructions (for example, appropriate steering signal). It should be understood that the invention is not limited by the type and kind of guided projectiles and guidance technique. According to another embodiment of the invention, the batteries or parts thereof can be aimed, e.g. moved relative to the platform, aligned, positioned or directed, prior to launch. According to this embodiment, the controller (element 30 illustrated in FIG. 2) is further configured for determining aiming instructions and generating of a suitable aiming control signal. According to an embodiment of the invention (not illustrated in FIG. 2), the countermeasure system (element 40 illustrated in FIG. 2) comprises or is integrated with suitable aiming means (e.g motorized aiming unit) abapted for aiming According to an embodiment of the invention, in order to facilitate very short reaction time and interception time, the movement of the batteries, and/or parts thereof, prior to launch, is measured and considered in determining the trajectory of the projectile.


The projectiles 41 are thus configured for accelerating to a high speed and for accurately maneuvering at such speeds to intercept the threat as quickly as possible, and as far away from the helicopter as possible. Further, the projectiles 41 comprise a non-fragmentation warhead that produces an explosion having an effective blast radius of about 1 meter or less, that will destroy, discharge or render ineffective any moving objects of an aerial threat within the blast radius. Furthermore, the casing of the projectiles 41, in particular of the warhead thereof, may be made from an ablatable material such as to burn away in the blast, thereby further minimizing any possibility of fragments from the destruction of the incoming threat to subsequently damage the helicopter.


Generally, it is preferable to employ light-weighted projectiles (e.g. to load the projectile with minimum amount of detonation required for protection). This will reduce the overall weight added to the platform, and allow equipping the platform with more projectiles. By way of non-limiting example, the interceptor projectiles 41 is a self guided and maneuvering, light weighted rocket of e.g. about 5 kg or less, carrying e.g. about 1 kg or 0.5 kg of detonation (or less), capable of traveling about 150-300 meters in a second. The amount of detonation carried by the projectile is dictated, inter-alia, by the accuracy of guidance, which in turn, depends, inter alia, upon accuracy of radar readings.


According to certain embodiments of the invention, countermeasure system 40 comprises a combination of projectiles capable of killing threats (e.g. generating blast that activate threat's warhead), and flairs capable of deceiving heat seeker and radar lock threats.


Radar System


According to an embodiment of the invention, radar system 20 comprises one or more sensors (antenna arrays) 21 (three sensors are shown in FIG. 2 by way of a non-limiting example). The sensors are located at selected locations onboard the helicopter, thereby providing required coverage.


According to an embodiment of the invention, the radar system is designed to perform detection as well as tracking and fire control. Typically, detection radars, e.g. as used in the Flight Guard™ system, are designed as wide angle radars. Typically, tracking radars have narrower field of view than detection radars. For example, the Trophy™ system uses wide angle radar for fire detection and narrow angle radar for tracking. However, in order to facilitate effective protection, the present invention makes use of a single radar system to perform threat detection and tracking. This could be achieved e.g. by a multi beam radar system, a digital multi beam radar system or a phased array radar system. According to an embodiment of the invention, the radar system is a 32-beam multi beam or digital multi beam radar system. According to an embodiment of the invention, the radar system is capable of performing detection as well as identification, tracking and fire control functions. Having the same radar performing detection, tracking and fire control functions contribute to better accuracy and better reaction time.


As is known to anyone versed in the art, accuracy, efficiency (e.g. in various weather conditions), antenna size as well as costs depend, inter-alia, on radar operation frequency range. Higher frequencies (e.g. 50-60 GHz) typically yield better accuracy and efficiency in bad weather conditions, require smaller antennas and are substantially expensive systems compared to lower frequencies. According to an embodiment of the invention, the radar system is designed to operate in the 10-20 GHz frequency range, wherein the required accuracy is achieved by means of suitable antenna size, radar design and radar data processing.


In order to enable very short reaction time (of about few tens and hundreds of milliseconds from detection up to launch) required for efficient protection from threats like RPG's, the radar system needs to be highly accurate e.g. providing angular accuracy of about one milliradian and range accuracy of about 0.5 meter or less. Preferably, the radar system is light weighted, of about 15 kg.


Control Unit (Controller)


For clarification, main processing operations are presented in the following as being carried by a stand-alone control unit 30. It should be understood that the control unit 30 is a hardware/software utility and as such its functions could be realized by one or more modules incorporated in the radar system 20; one or more modules incorporated in the countermeasure system 40; or certain control functions and operations could be realized by modules incorporated in the radar system 20, while others by modules incorporated in the countermeasure system 40. Further, such a control unit may be integrated with, or the functions thereof provided by, the fire control computer or the mission computer of the helicopter 100, when the helicopter is fitted with such a computer.


According to an embodiment of the invention, the controller 30 is configured to perform the following sequence of control operations 300, as illustrated in FIG. 3:


Operation 310—Threat detection, identification and tracking: radar data regarding airspace around the platform (e.g full airspace hemisphere around the helicopter; half hemisphere above or below the helicopter; or selected zones in the vicinity of the helicopter) is dynamically analyzed. A threat is detected and identified, e.g. based on comparison of threat signature to a lookout table; comparison of threat velocity to a threshold velocity; analysis of approach direction (angle), range and velocity; build up of threat trajectory based on data corresponding to several measurements, and the like. Trajectory and velocity of the platform may also be considered, e.g. in order to minimize effect of reflections from the platform itself.


Upon identification, the threat is tracked, and output data, including threat output data corresponding to velocity, range and an angle of the threat with respect to the platform, is dynamically generated.


Operation 320—trajectory calculations and determination of engagement point: In accordance with operational requirements, the desired engagement point (point EP illustrated in FIG. 1) is determined, based on calculation and prediction of threat and projectile trajectories.


According to an embodiment of the invention, the engagement point is determined such that neutralization of the threat may occur at a safe distance away from the helicopter (distance R illustrated in FIG. 1). According to another embodiment of the invention, the engagement point is selected such that direct hit of the threat by the projectile is expected. According to yet another embodiment of the invention, best suitable for protection against RPG's, the engagement point is determined such that blast generated by explosion of the projectile's warhead will most probably discharge the threat's warhead before it reaches the platform.


According to an embodiment of the invention, operation 320 includes calculation, for each moving object whether it is expected to intercept and collide with the helicopter 100 or not, at the predicted flight path of the helicopter 100. The moving objects which are determined to have a trajectory relative to the helicopter 100 that does not present a threat thereto, and will fly at a safe enough distance that even if it detonates no damage may be expected to the helicopter, may optionally be ignored, or optionally destroyed. However, for each of the moving objects which are considered to pose a threat to the helicopter, for example calculated to pass sufficiently close to the helicopter to collide with it or such that a detonation of a warhead carried thereby may cause damage to the helicopter, a command signal is generated and transmitted to the battery 40 for launching one or more interceptor projectiles 41 to counter the threat.


Operation 330—CM (countermeasure) analysis and generation of a fire control command: Upon identification of the threat and the determination of a suitable engagement point, a suitable countermeasure device is also determined. In accordance with various embodiments of the invention, by way of non-limiting example only, the following control parameters are considered in order to determined the suitable CM device: time of launch; direction of launch; selection of battery from which the projectile is to be launched; selection of a specific projectile from a specific battery to be launched; determination of number and order of projectiles to be launched; explosion time of projectile's warhead; updated guidance information.


According to one embodiment of the invention, a result of an approach analysis, e.g. identifying a threat approaching the platform (as opposed to detection of a non-approaching threat in the vicinity of the platform) will dictate the reaction of the protection system. Three non-limiting examples of the above are: (i) in response to approach detection and above a predefined threshold closing velocity and/or range and/or direction, a projectile will be launched from the platform without performance of preliminary platform maneuver; (ii) in formation flight, each platform conduct approach analysis that includes identification of approach toward the platform as well as toward the formation, based upon the platform role in the formation; and (iii) in response to approach detection and above a predefined threshold closing velocity and/or range and/or direction, a projectile will be launched from the platform even in a case where not enough radar data is measured in order to determined the engagement point and guidance data, prior to launch.


According to certain embodiments of the invention, by way of a non-limiting example only, and in order to comply with certain operational requirements and constraines, alternative or additional control parameters are considered, as follows: height of flight; formation flight details; terrain details; mission details and the like.


It should be understood that various operational scenarios could be addressed by the protection system, without departing from the scope of the present invention. By way of a non-limiting example, such operational scenarios may encompass the following: detection and identification of a threat without launch of a countermeasure projectile (e.g. when such a launch may endanger other platforms or humans operating in the vicinity of the threatened platform; in formation flight, launch of a countermeasure projectile to intercept a threat endangering neighboring platform; in a networked environment, receiving alert of a threat and/or fire control command (including guidance information) from an external source (e.g. protection system mounted onboard another platform which is a member of the same network).


According to one embodiment of the invention, the controller 30 may be adapted for operation when the helicopter is flying in proximity to other friendly aircraft including other helicopters, for example. Such proximity flying may include formation flying, for example. In such cases, the control unit 30 may be further adapted to identify whether other flying objects, e.g. as picked up by the helicopter radar, in particular radar system 20, and/or by using position information shared between friendly members of a communication network, are friendly aircraft. Having positively identified one or more friendly aircraft, the operation of the system 10 may be modified as follows. First, the controller 30 generates location and trajectory data for each friendly aircraft from data provided by the radar system 20, in a similar manner to that described with respect to an aerial threat, mutatis mutandis. Then, the controller determines whether the interception trajectories for the projectiles 41, and their blast radius when neutralizing the aerial threat, would endanger the friendly aircraft, at their projected positions. If the determination is that no danger is posed, then the projectiles are launched as before. On the other hand, if the projectile trajectories, or their blast radius could cause damage, then a different course of action is taken, e.g. in the case of a UAV operating in proximity to other platforms or forces, a decision to sacrifice the threatened UAV in order to save the other forces or platforms, could be taken


Operation 340—transmitting control command to the countermeasure system: According to one embodiment of the invention, the projectile is preprogrammed with flight directions prior to launch. According to another embodiment of the invention, best suitable for protection against fast approaching threats, the projectile is a guided rocket and guidance information is dynamically calculated and transmitted to the projectile (uplink communication). According to another embodiment of the invention, the control command includes aiming instructions that will be carried out by a suitable aiming unit, for aiming the battery itself or parts thereof.


In order to facilitate launch and guidance of more than one projectile (parallel operation), each projectile is assigned (e.g. by the controller, the radar or the battery) with an identity, and this identity is used (e.g. by the controller, radar, guidance system) for generating the appropriate guidance updates. The identity of the projectile is also used for communicating with the projectile. According to an embodiment of the invention, each projectile is assigned with an identity prior to launch. Upon launch the identity is used by all components of the active protection system in all processing operations relating to the same projectile. The guidance information that is generated by the guidance system is respectively assigned with the identities of the projectiles that were launched, and each projectile is responsive to the guidance information that is assigned to its own identity.


In order to simplify explanations, the operations carried out by the control unit were presented as discrete operations, carried out in a sequential manner. It should be understood that the above detailed control operations are carried out rapidly, in a dynamic and iterative manner. For example, the determination of the engagement point is done iteratively based on newly measured radar data, and updated guidance information is generated and transmitted to the projectile in a dynamic manner. In order to achieve very short reaction time and interception time, the control unit as well as the radar system, are adapted for high update rate, in order to provide the projectile with rapid and accurate guidance updates, needed to intercept the target e.g. at 30-50 meters away from the helicopter in about 300 milliseconds.


The concept of the invention was described mainly with reference to a simplified scenario, where only one projectile is launched against only a single threat. It should be understood that where the aerial threat comprises more than one moving object, the trajectory of each object is separately determined and tracked in parallel. The same applies to the case where more than one projectile is launched against a threat. Thus, each of the above detailed operations 310-340 is repeated as many times as required.


In the above description, it is assumed that the protection system is integrated or designed to interface with platform systems and instrumentation, such that information collected by these systems is available to the protection system. For example, platform data (e.g. speed, direction of flight, attitude, altitude and so on) is externally provided to the protection system. It should be understood that the protection system may include additional elements to those described above with reference to FIG. 2, in order to autonomously acquire all necessary information.


The aforesaid reaction time of the system 10 may be defined as the minimum elapsed time required by the system 10 to identify a threat, calculate an interception trajectory for a projectile 41 based on the trajectory of the threat and of the helicopter, and launch at least one missile so that it destroys or neutralize the threat at a sufficiently spaced distance from the helicopter such that the blast, and possible debris created thereby, will not damage the helicopter. Such a reaction time may be, for certain operational needs, for example from a few milliseconds, tens and hundreds of milliseconds up to a few seconds, as the operational requirements dictate, and the blast may be required to be more than 30 meters away from the helicopter 100.


As described before, in order to provide such a short reaction time, the protection system is designed with a highly accurate, wide angle multi-beam or phased-array radar system capable of detection, identification, tracking and fire control. The radar system is designed with several sensors located on different locations onboard the platform. Thus, the radar is capable of providing very accurate output data in a relatively very short time. Furthermore, the countermeasure system preferably is designed to have several batteries of projectiles located at different locations onboard the platform, thus enabling selecting the suitable countermeasure projectile which provides maximum kill success. Good reaction time is also achieved due to the efficient control processing schemes, e,g, as described above with reference to FIG. 3. Good reaction time is achieved by aiming the projectile battery—or parts thereof—prior to launce. The use of guided or self-guided (maneuvering) projectiles together with efficient guidance processing further reduce reaction time.


In embodiments of the present invention, the radar system 20 is critical to the effectiveness of the protection system 10, and the operation parameters of the radar system are defined, at least in part, by the type of threat and a minimum safety distance R away from the helicopter 100 at which the threat 120 can be intercepted. The engagement distance R may be determined from a variety of factors such as, for example, the sensitivity of the radar system 20, the time necessary to actuate the countermeasure system 40 to launch the projectile 41, the effectiveness, accuracy acceleration and speed of the projectile 41, and the nature of the platform 100 to be protected.


While the invention has been described in the context of an airborne vehicle such as a helicopter, the system 10 may be configured for operation with any other suitable aircraft, including small or large, manned or unmanned, fixed wing or rotor aircraft, or balloons or other types of air vehicles.


The system 10 may be configured for operation at a location for the protection thereof, for example a building, communication or radar installation, a camp, and so on, in a similar manner to that described above, mutatis mutandis, with the optional difference that weight constraints may be even more relaxed than in the case of moving vehicles, and furthermore, the radar system 20, controller 30 and batteries may optionally be significantly distanced one from another. For example, a central radar system may be provided in a camp, while at the same time providing a plurality of batteries at the periphery of the camp.

Claims
  • 1-40. (canceled)
  • 41. An active protection system mountable onboard an aerial platform for protecting the aerial platform, the protection system comprising: a multi-beam or phased array radar system configured for generating output data including threat output data corresponding to a velocity, a range, and an angle of a threat with respect to the aerial platform in an airspace around the platform, said output data being useful for detecting, identifying and tracking of at least one threat approaching the platform, said radar system enabling reduced weight of the protection system, and a reduced response time of the protection system;a countermeasure system comprising a plurality of projectiles and being capable of launching at least one projectile in response to receiving a control command; anda control unit configured and operable for receiving and analyzing said output data from said radar system, to thereby detect, identify and track said at least one threat approaching the platform; determining a desired engagement point for said at least one threat; and utilizing said determined desired engagement point for generating the control command indicative of selection of one or more projectiles from said plurality of projectiles suitable for intercepting said threat at said engagement point and transmitting said control command to said countermeasure system, thereby enabling countering said threat.
  • 42. A system according to claim 41, wherein the selected projectile is suitable for engagement with said threat at said engagement point by at least one of a type of the projectile and its location within the platform.
  • 43. A system according to claim 41, wherein said platform is one of the following platforms: helicopter, UAV (Unmanned Airborne Vehicle), RPV (Remotely Piloted Vehicle), light aircraft, hovering platform, low speed traveling platform.
  • 44. A system according to claim 41, wherein said threat is one of the following threats: non-guided missile or rocket; guided missile or rocket; self-guided and maneuvering missile or rocket; heat seeking missile or rocket; radar lock missile or rocket; laser guided missile or rocket; short range missile or rocket; shoulder missile or rocket; RPG (Rocket Propelled Grenade); TOW (Tube-launched, Optically tracked, Wire-guided missile); Hot; Milan; Cornet; Stinger; Strela; and Sager.
  • 45. A system according to claim 41, wherein said projectile is one of the following: non-guided rocket or missile; guided rocket or missile; and self-guided and maneuvering rocket or missile.
  • 46. A system according to claim 41, wherein said multi-beam or phased array radar system comprises one or more sensor units, located at selected locations onboard the platform.
  • 47. A system according to claim 41, wherein said radar system is further configured for tracking of said at least one projectile, and generating output data corresponding to a velocity, a range and an angle of the projectile with respect to the platform.
  • 48. A system according to claim 41 wherein said multibeam radar system comprises a digital multibeam radar.
  • 49. A system according to claim 48 wherein the radar system is a 32-beam multi-beam radar system.
  • 50. A system according to claim 49 wherein the radar system is designed to operate in a 10-20 GHz frequency range.
  • 51. A system according to claim 41, wherein weight of said radar system is in the range of 10-100 Kg.
  • 52. A system according to claim 41, wherein said countermeasure system comprises one or more recoilless battery of the projectiles, located at selected locations onboard the platform, and is associated with at least one activation unit, the activation unit being operatively connected to the control unit and configured for responding to a command signal from the control unit by launching one or more projectiles.
  • 53. A system according to claim 41, wherein said countermeasure system comprises at least one recoilless battery of the projectiles, associated with at least one activation and aiming unit, the activation and aiming unit being operatively connected to the control unit and configured for responding to a command signal from the control unit by aiming and launching one or more projectiles.
  • 54. A system according to claim 53 wherein said aiming is performed by aiming the battery as a whole or by aiming at least one part thereof.
  • 55. A system according to claim 41, wherein said countermeasure system is further capable of launching flairs and/or chaffs.
  • 56. A system according to claim 41, further comprising a guidance system capable of guiding the projectile toward an engagement with the threat.
  • 57. A system according to claim 41, further comprising communication unit operable to facilitate at least uplink communication with the projectile, thereby enabling guiding the projectile toward a predicted engagement point with the threat.
  • 58. A system according to claim 41, wherein said control unit is a hardware/software utility configured for performing the following operations: (a) detecting, identification and tracking the threat based on processing of said output data from the radar system;(b) calculating at least trajectory of the threat and the platform and determining the engagement point for the detected threat with respect to the platform;(c) determining said at least one suitable projectile to be launched, if at all, and generating the control command comprising a fire control command; and(d) repeating any of operations (a) to (c) as many times as required.
  • 59. The system according to claim 58, wherein said control command generated by the control unit comprises an aiming and fire control command.
  • 60. A system according to claim 58, wherein said control unit is communicatively coupled to platform instrumentation for receiving at least platform trajectory data and said calculating is carried out based on platform trajectory data received from said platform instrumentation.
  • 61. A system according to claim 58, wherein said control unit is further configured for processing platform trajectory data based on said output data, and said calculating is carried out based on said platform trajectory data.
  • 62. A system according to claim 58, wherein said transmitting said control command to said countermeasure system is carried out prior to launch.
  • 63. A system according to claim 58, wherein said transmitting said control command to said countermeasure system is carried out in a dynamic manner prior to launch and afterwards.
  • 64. A system according to claim 41, wherein said plurality of projectiles comprises substantially non-fragmentation type projectiles.
  • 65. A system according to claim 58, wherein said control unit is further configured for tracking said at least one projectile, after it was launched, and to perform operations (b) and (c) based on information corresponding to velocity, range and angle of the projectile with respect to the platform that is measured after launch.
  • 66. A system according to claim 41, wherein said countermeasure system comprises one or more battery of the projectiles, each located at different locations onboard the platform, the control unit being configured and operable for selecting one from among said batteries, in accordance with a predefined criteria, for launching the projectile, and directing the command signal accordingly.
  • 67. An active protection method for protecting an aerial platform against an approaching threat, the protection method comprising: (a) generating radar output data measured by a multi beam or phased array radar system mounted onboard the aerial platform, the output data including threat output data corresponding to a velocity, a range and an angle of the threat with respect to the aerial platform in an airspace around the platform, and detecting, identifying and tracking of at least one threat approaching the platform based on processing of at least said output data, thereby providing a reduced response time of the protection system;(b) providing onboard the platform a countermeasure system comprising a plurality of projectiles and being capable of launching at least one projectile in response to receiving a control command;(c) receiving and analyzing said output data, and detecting, identifying and tracking said at least one threat approaching the platform;(d) determining a desired engagement point for said at least one threat;(e) utilizing said determined desired engagement point for generating said control command, indicative of selection of one or more projectiles from said plurality of projectiles suitable for intercepting said threat at said engagement point; and,(f) transmitting said control command to said countermeasure system thereby enabling countering said threat.
  • 68. A method according to claim 67, wherein the selected projectiles are suitable for engagement with said threat at said engagement said engagement point by at least one of a type of the projectile and its location within the platform.
  • 69. A method according to claim 67, wherein said platform is one of the following platforms: helicopter, UAV (Unmanned Airborne Vehicle), RPV (Remotely Piloted Vehicle), light aircraft, hovering platform, low speed traveling platform.
  • 70. A method according to claim 67, wherein said threat is one of the following threats: non-guided missile or rocket; guided missile or rocket; self-guided and maneuvering missile or rocket; heat seeking missile or rocket; radar lock missile or rocket; laser guided missile or rocket; short range missile or rocket; shoulder missile or rocket; RPG (Rocket Propelled Grenade); TOW (Tube-launched, Optically tracked, Wire-guided missile); Hot; Milan; Cornet; Stinger; Strela; and Sager.
  • 71. A method according to claim 67, wherein said generating radar output data is carried out based on measurements received from one or more sensor unit, located at selected locations onboard the platform.
  • 72. A method according to claim 67, further comprising: (g) tracking of said at least one projectile, and generating countermeasure output data corresponding to a velocity, a range and an angle of the projectile with respect to the platform.
  • 73. A method according to claim 67, further comprising: (h) providing uplink communication with the projectile, thereby enabling guiding the projectile toward a predicted engagement point with the threat.
  • 74. A method according to claim 67, further comprising: (i) calculating at least trajectory of the threat and the platform and determining the engagement point for the detected threat with respect to the platform;(j) determining said at least one suitable projectile to be launched, if at all;(k) repeating any one of operations (a) to (g) as many times as required.
  • 75. A method according to claim 67, wherein said transmitting said control command to said countermeasure system is carried out prior to launch.
  • 76. A method according to claim 67, wherein said transmitting said control command to said countermeasure system is carried out in a dynamic manner prior to launch and afterwards.
  • 77. A method according to claim 74, further comprising tracking said at least one projectile, after it was launched, and performing said calculating operation and/or determining operation based on information corresponding to velocity, range and angle of the projectile with respect to the platform, measured after launch.
  • 78. A method according to claim 74, wherein the countermeasure system comprises one or more battery of the projectiles each located at different locations onboard the platform, operation (j) further comprising: selecting one from among said batteries, in accordance with a predefined criteria, for launching the projectile, and directing the command signal accordingly.
  • 79. A method according to claim 67, further comprising: (l) receiving platform trajectory data from platform instrumentation; and wherein said calculating is carried out based on platform trajectory data received from said platform instrumentation.
  • 80. A method according to claim 67, further comprising: (i) processing platform trajectory data based on said output data; and wherein said calculating is carried out based on said platform trajectory data.
Priority Claims (1)
Number Date Country Kind
178221 Sep 2006 IL national
PCT Information
Filing Document Filing Date Country Kind 371c Date
PCT/IL07/01153 9/20/2007 WO 00 3/19/2009