U.S. patent application number 12/442053 was filed with the patent office on 2010-02-04 for active protection method and system.
This patent application is currently assigned to ELTA SYSTEMS, LTD.. Invention is credited to David Longman, Jacob Tzlil.
Application Number | 20100026554 12/442053 |
Document ID | / |
Family ID | 39092931 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100026554 |
Kind Code |
A1 |
Longman; David ; et
al. |
February 4, 2010 |
ACTIVE PROTECTION METHOD AND SYSTEM
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.
Inventors: |
Longman; David; (Pardesiya,
IL) ; Tzlil; Jacob; (Rishon LeZion, IL) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
ELTA SYSTEMS, LTD.
Ashdod
IL
|
Family ID: |
39092931 |
Appl. No.: |
12/442053 |
Filed: |
September 20, 2007 |
PCT Filed: |
September 20, 2007 |
PCT NO: |
PCT/IL07/01153 |
371 Date: |
March 19, 2009 |
Current U.S.
Class: |
342/62 ; 102/336;
102/501; 244/3.1; 244/3.14; 342/107; 342/67; 89/1.7 |
Current CPC
Class: |
F41G 7/301 20130101;
F41G 5/08 20130101; F41G 7/224 20130101 |
Class at
Publication: |
342/62 ; 89/1.7;
244/3.1; 102/336; 244/3.14; 102/501; 342/107; 342/67 |
International
Class: |
G01S 13/88 20060101
G01S013/88; F41A 1/08 20060101 F41A001/08; F41G 7/00 20060101
F41G007/00; F42B 4/26 20060101 F42B004/26; F41G 7/30 20060101
F41G007/30; F42B 12/42 20060101 F42B012/42; F42B 12/70 20060101
F42B012/70; F42B 12/02 20060101 F42B012/02; G01S 13/58 20060101
G01S013/58; G01S 13/42 20060101 G01S013/42; G01S 13/00 20060101
G01S013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 20, 2006 |
IL |
178221 |
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; and a 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.
Description
FIELD OF THE INVENTION
[0001] 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
[0002] A variety of methods are known relating to protecting a
vehicle or the like from a destructive threat.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] One active protection defense system is the Flight Guard.TM.
system available by Israel Aircraft Industries.TM. Ltd. and Elta
Systems.TM. Ltd., Israel. The Flight Guard.TM. 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.TM. system is described
e.g. at
www.israeli-weapons.com/weapons/aircraft/systems/flight_guard/Flight_Guar-
d.htm).
[0007] Another active protection defense system is the Trophy.TM.
system marketed by General Dynamics.TM., USA and designed by a
consortium comprising Rafael Armament Development Authority Ltd.,
Israel Aircraft Industries.TM. Ltd., Elta Systems.TM. Ltd and
Israel Military Industries.TM. Ltd., Israel. The Trophy.TM. 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.TM. 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).
[0008] The following publications are also of interest: U.S. Pat.
Nos. 7,059,567 and 5,661,254; US Patent application No.
2006/0103569.
[0009] 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).
[0010] 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
[0011] 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.
[0012] 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.
[0013] 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:
[0014] 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;
[0015] a countermeasure system capable of launching at least one
non-fragmentation interceptor projectile in response to receiving a
control command;
[0016] 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
[0017] 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.
[0018] 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.
[0019] 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.
[0020] According to an embodiment of the invention, the control
unit is a hardware/software utility configured for performing the
following operations: [0021] (a) detecting, identification and
tracking the threat based on processing of the output data; [0022]
(b) calculating at least trajectory of the threat and the platform
and determining an engagement point between the threat and the
projectile; [0023] (c) determining at least one suitable projectile
to be launched, if at all, and generating fire control command; and
[0024] (d) repeating any of operations (a) to (c) as many times as
required.
[0025] According to another embodiment of the invention, the
control unit is a hardware/software utility configured for
performing the following operations: [0026] (a) detecting,
identification and tracking the threat based on processing of the
output data; [0027] (b) calculating at least trajectory of the
threat and the platform and determining an engagement point between
the threat and the projectile; [0028] (c) determining at least one
suitable projectile to be launched and, if at all, and generating
aiming and fire control command; and [0029] (d) repeating any of
operations (a) to (c) as many times as required.
[0030] 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.
[0031] According to another aspect of the invention there is
provided an active protection method for protecting a platform
against an approaching threat, comprising: [0032] (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; [0033] (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; [0034] (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.
[0035] 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
[0036] 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:
[0037] FIG. 1 is a schematic representation of an active protection
system according to an embodiment of the invention;
[0038] FIG. 2 is a more detailed representation of an active
protection system according to an embodiment of the invention;
and
[0039] 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
[0040] 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.
[0041] 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.
[0042] 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.
[0043] Countermeasure System
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] Radar System
[0052] 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.
[0053] 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.TM. system, are designed as wide angle radars.
Typically, tracking radars have narrower field of view than
detection radars. For example, the Trophy.TM. 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.
[0054] 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.
[0055] 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.
[0056] Control Unit (Controller)
[0057] 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.
[0058] 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:
[0059] 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] 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.
[0064] 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.
[0065] 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.
[0066] 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.
[0067] 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).
[0068] 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
[0069] 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.
[0070] 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.
[0071] 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.
[0072] 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.
[0073] 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.
[0074] 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.
[0075] 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.
[0076] 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.
[0077] 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.
[0078] 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.
* * * * *
References