Aircraft protection system and method

According to one embodiment of the invention, a system for protecting aircraft includes a plurality of missile warning sensors and a turret mounted near the top of at least one support structure. Each missile warning sensor is operable to detect a missile and the turret is operable to emit a laser beam that is directed toward the missile to divert the missile from its intended flight pattern.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to the field of aircraft protection and, more particularly, to a system and method that protects aircraft from ground-based missiles, such as Infrared Man Portable Air Defense Systems (MANPADS).

BACKGROUND OF THE INVENTION

Fears of attacks on aircraft, especially commercial aircraft, involving shoulder-launched missiles have increased since the terrorist attacks on American soil on Sep. 11, 2001. Shoulder-launched missiles are no doubt in the hands of some of the world's most dangerous terrorist groups, such as Al Qaeda and Hezbollah.

There are several types of shoulder-launched missiles. All are about five feet long and weigh less than forty pounds, which makes them highly mobile. The U.S.-made Stinger and Russian-made SA-7 Strela are the two most widely used types of shoulder-launched missiles by terrorists in attacks dating back to 1996. Each has a range of over three miles and uses a heat-seeking infrared (IR) guidance system to hone in on targets. In addition to their mobility and weight, these weapons are dangerous because they require very little training in order to operate.

While small aircraft are vulnerable to MANPAD attacks, larger aircraft, such as commercial airliners, are at greater risk because they present a greater IR heat source for the incoming missile. Additionally, current IR guided missile sensors have very narrow fields of view, and thus dispersed engines on a larger aircraft present several targets to the incoming missile. Large aircraft are particularly vulnerable during takeoff and landing because they are lower to the ground, and when landing, are moving at a slower velocity.

Current aircraft protection involves on-board countermeasures, such as pyrotechnic flares and on-board turret-based IR jammer systems. Flares pose a high risk of fire to the surrounding areas, and during takeoff and landing, when the aircraft is most vulnerable, they lack the airspace needed to disperse and act as a decoy for the incoming missile. On-board, turret-based IR jammer systems are very effective, since they would generally be in the field of view of the approaching target, but with each ship set cost ranging between one and two million dollars, outfitting all 6,800 commercial airliners to date would be a costly venture.

SUMMARY OF THE INVENTION

According to one embodiment of the invention, a system for protecting aircraft, including one ore more supports positioned adjacent a flight pattern of the aircraft, one or more missile warning sensors coupled to at least one of the supports, one or more turrets coupled to at least one of the supports, and a controller. Each of the one or more missile warning sensor is operable to detect a missile when launched. Each of the one or more turrets is operable to emit a laser toward the missile. And the controller is operable to control the emission of the laser beam in response to detection of the launched missile.

Embodiments of the invention provide a number of technical advantages. Embodiments of the invention may include all, some, or none of these advantages. A ground-based missile defense system according to one embodiment is significantly lower in cost (especially considering maintenance costs) than outfitting all commercial airlines with a missile defense system. Using a ground-based system also results in significantly fewer false alarms, and is safer than a pyrotechnic flare system that may be used on board an aircraft. Deployment of a ground-based system facilitates large, heavy traffic airports being outfitted first, followed by smaller, less traffic airports.

Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Example embodiments of the present invention and their advantages are best understood by referring now toFIGS. 1A through 6Bof the drawings, in which like numerals refer to like parts.

FIGS. 1A and 1Bare elevation and plan views, respectively, of a system100for protecting aircraft from a shoulder-launched missile attack, according to one embodiment of the present invention.FIGS. 1A and 1Billustrate an aircraft102near an aircraft runway114and a terrorist104, which may be any suitable bad person, using an Infrared Man Portable Air Defense System (“MANPAD”) to shoot a missile106towards aircraft102. Examples of MANPADs are the U.S.-made Stinger and Russian-made SA-7 Strela. The present invention contemplates any suitable device to launch missile106. Although aircraft102is illustrated inFIGS. 1A and 1Bas a commercial airliner, the present invention contemplates aircraft102being any suitable flying object, such as a military aircraft or helicopter, corporate jet, commuter aircraft, or freight hauling aircraft.

In the illustrated embodiment, system100includes a plurality of support structures108positioned adjacent a flight pattern of aircraft102and an integrated controller110. The flight pattern of aircraft102can be an aircraft landing or takeoff. As described in further detailed below in conjunction withFIG. 3, one or more missile warning sensors302and/or one or more turrets304are coupled to structures108in accordance with an embodiment of the invention. Missile warning sensors302and turrets304work in conjunction with one another to detect the launch of missile106toward aircraft102and emit a laser112toward missile106to divert it from its intended path. Controller110, which may be any suitable device that executes logic, is operable to synchronize laser beams112emitted by respective turrets304to maximize their effectiveness in diverting missile106from its intended path, or destroying the missile in flight, thereby assuring that aircraft102lands or takes off safely. The diversion of missile106is illustrated inFIG. 1B. Communication of missile warning sensors302, turrets304, and/or controller110between each other may be accomplished through any suitable link, such as a wireless link or ground lines, through the use of any suitable interface protocol.

Support structures108may be any suitable support structures. In the illustrated embodiment, support structures108are steel-framed structures that extend vertically upward. Support structures108may be any suitable height and may be spaced apart with any suitable spacing. In addition, the number of support structures108in addition to the arrangement of support structures108are all variable depending upon the geographic location of runway114, number of runways, size of protection corridor, and the surrounding topography. The present invention illustrates any suitable arrangement of support structures108within the teachings of the present invention, from randomly positioning support structures108, as illustrated inFIG. 1B, to strategically positioning support structures108. The strategic positioning of support structures108is described in greater detail below.

FIG. 2is a plan view of system100(FIG. 1A), according to another embodiment of the invention, illustrating some support structures108aligned in a straight line with one another, in addition to the use of extra tall support structures202to potentially increase the effectiveness of system100. Some missiles106have a very long range (4 kilometers) and can reach elevations in excess of ten thousand feet. Therefore, extra tall support structures, such as support structures202may be utilized. In one embodiment, support structures202reach an elevation of a thousand feet or more, which is similar to radio towers now in existence.

FIG. 3is a schematic of a top portion of an example support structure108illustrating a plurality of missile warning sensors302and a plurality of turrets304mounted near the top of support structure108in accordance with an embodiment of the present invention. Although the embodiment depicted inFIG. 3illustrates a plurality of missile warning sensors302and turrets304, the present invention contemplates any suitable number of missile warning sensors or turrets coupled to support structure108. In some embodiments, either missile warning sensors302or turrets304are coupled to support structure108, but not both. Missile warning sensors302and turrets304may be positioned at or near the top, or at any other suitable location of support structure108, and may be coupled in any suitable manner. Referring back toFIGS. 1A and 1B, generally, missile warning sensors302function to sense missile106being launched by terrorist104towards aircraft102and turrets304function to emit a laser beam112towards missile106, in order to divert, disrupt, or distract missile106from its intended path, so it does not strike and destroy aircraft102. This process is described in greater detail below.

Missile warning sensors302are well known in the industry and, accordingly, any suitable missile warning sensors may be utilized. Generally, missile warning sensors302, depending on the type of missile warning sensor utilized, looks in its respective band, such as an ultraviolet band or an IR band, and looks for an increase in either ultraviolet or IR power (energy). This increase in energy indicates an ignition source. Missile warning sensors302then send a signal to turrets304regarding the incoming missile106(FIGS. 1A–1B) so that turret304may perform its function. Typically, missile warning sensors302are disposed around the perimeter around the top of support structure108and angled in a manner that provides sufficient coverage to sense missile106being launched. However, as described above, missile warning sensors302may be positioned at any other suitable location of support structure108.

Turrets304are well known in the industry and, accordingly, any suitable turrets may be utilized. In the illustrated embodiment, turret304utilizes a multi-band laser function that provides protection against all probable threats. Turret304, in one embodiment, is able to rotate 360 degrees in azimuth and up to + and −90 degrees in elevation in order to point towards missile106. Turret304, after receiving a signal from one or more missile warning sensors302, emits a laser beam112(FIGS. 1A–1B), using the appropriate wavelength and waveform, at missile106(FIGS. 1A–1B) in order to divert, disrupt, or distract missile106from its intended path. In one embodiment, turret304includes an infrared fine tracker that is able to hone in on the location of missile106in order to emit laser112in the proper direction. Turret304may use any type of feedback system that identifies the missile, then determines the appropriate wavelength and waveform (closed-loop system) before emitting laser112with the determined, appropriate wavelength and waveform, or can simply emit a laser112that contains a multitude of wavelengths (open-loop system) and uses a generic waveform to defeat the missile.

Laser beams112(FIGS. 1A–1B) emitted by turrets304will typically have different levels of effectiveness. Laser beams not colocated with the target aircraft rely on optical scatter and reflections (“OSAR”) to divert the missile, whereas laser beams that are colocated with the target aircraft may concentrate greater infrared energy towards the missile and be more effective in diverting the missile from its intended path. The farther the laser beam is off the bore sight of the missile, the more power is needed to divert it. This is one reason why it is preferred that there be multiple support structures108arranged in a strategic pattern and at different heights to minimize the angles between the turret position304and target aircraft in order to be most effective on incoming missiles.

Referring back toFIG. 2as an example, by placing turrets304in specific locations on support structures108, and positioning support structures108in strategic locations through the protection corridor of aircraft102, one can optimize the effectiveness of turrets304. Support structures108and turrets304can be expensive, and therefore obtaining the same level of effectiveness with less support structures108and turrets304is referred to as optimization. In the illustrated example embodiment, a plurality of support structures108are strategically positioned throughout the protection corridor of aircraft102, in varying heights to parallel the flight path of aircraft102as it takes off from or lands on runway114. Additionally, extra tall support structures202aand202bmay be used in order to reduce the OSAR angle. Therefore, when terrorist104fires missile106at aircraft102as it takes off from runway114, system100may be more effective in diverting missile106from aircraft102because lasers112are aimed at the field of view of the front of missile106, which means that more energy is concentrated on the missile. In the illustrated embodiment, laser beams112a–112cwould be more effective than lasers112d–112gbecause laser beams112a–112care pointed directly toward the oncoming missile106, while lasers112d–112g, while pointed at the front of missile106, are not in the direct line of sight of the front of missile106, therefore, lasers112a–112cconcentrate more energy on missile106than lasers112d–112g. Determining the optimal number and placement of extra tall support structures202, support structures108, and turrets304adjacent an aircraft flight path may depend on a number of factors, such as budget, zoning, aesthetic, air traffic, number of runways, and topography issues.

In one embodiment, the lasers used in turret304are of sufficient power that when combined with laser beams from all other turrets304could either disable the missile106electronics or destroy missile106.

FIGS. 4A through 4Gillustrate additional embodiments of the invention in which different support methods are utilized for the missile warning sensors302and/or turret(s)304. These support structures may further reduce the cost of implementing a system for protecting aircraft disclosed by the present invention. As illustrated byFIG. 4A, a building404may be utilized to support a small structure402with missile warning sensors302and turrets304coupled thereto. As illustrated byFIG. 4B, the tops or sides of mountains and/or hills406may be used to support missile warning sensors302and turret304or a small structure402with missile warning sensors302and turrets304. As illustrated byFIG. 4C, a mobile device408with or without extendable small structures420may be used to support missile warning sensors302and turrets304. As illustrated byFIG. 4D, a low-mounted ground-based support structure410may be utilized to support missile warning sensors302and turret304. As illustrated byFIG. 4E, targeted aircraft102may be used as a reflective surface. Therefore, during a missile launch the lasers112will point at the surface of targeted aircraft102, which will reflect the laser energy412back in all directions, including at missile106, thereby causing missile106to miss the intended target. As illustrated byFIG. 4F, an existing radio, television or other type of antenna tower or structure414may be used to support missile warning sensors302and turrets304. And as illustrated byFIG. 4G, a tethered balloon416may be utilized to support missile warning sensors302and turrets304. In this embodiment, the power and communication may come from a ground station418. Other suitable methods of supporting and/or housing missile warning sensors302and turrets304are contemplated by the present invention.

FIG. 5Aillustrates an embodiment of system100, in which the central controller110alerts aircraft102of missile106being launched by terrorist104. In the illustrated embodiment, one or more missile warning sensors302(FIG. 3) detect missile106being launched by terrorist104and notify central controller110of the missile launch. Central controller110then directs all turrets304to point at the missile106and emit a laser beam with a jamming waveform or a destructive laser beam. In another embodiment, controller110relays to control tower502that terrorist104launched a missile at aircraft106, and control tower502then relays this notification to aircraft102.

FIG. 5Billustrates an embodiment of system100described in conjunction withFIG. 1A, which includes a missile tracking and alert system. In the illustrated embodiment, controller110receives tracking data of missile106from missile warning sensors302(FIG. 3), calculates the point of origin of the launch of missile106(also the location where terrorist104launched missile106) and calculates the point of impact of missile106. In a particular embodiment, controller110triangulates missile tracking data received from turrets304to calculate the points of impact and origin of missile106. Controller110then alerts security units504of the calculated point of origin of missile106so that security unit504can take any suitable action, such as investigating the calculated point of origin, as well as any suitable adjoining region, for the presence of terrorist104. Any suitable security unit504may be alerted, such as one or more of the following: airport security, police, armed forces, and/or federal agencies. Controller110may also alert a response unit506of the calculated point of impact of missile106so that response unit506may take any suitable action, such as disarming the warhead if it is determined the missile did not explode, containing and/or suppressing any fires the impact missile106may have caused, assessing damage created by the impact of missile106, and/or providing emergency medical services to individuals that may have suffered any injury due to missile106impacting the point of impact. Any suitable response unit506may be alerted, such as one or more of the following: fire department, medical alert, and/or bomb squad. Other suitable entities may also be notified by controller100, such as a hospital. Upon declaration of missile106launch, system100may give specific instructions to all aircraft102, both in the air and on the ground, to proceed to predetermined positions until the airfield and air space are secure.

FIGS. 6A and 6Bare flow diagrams illustrating an example method of alerting, and tracking, respectively, a missile launch towards an aircraft. With reference toFIGS. 1A and 1B, after terrorist104launches missile106at aircraft102, as denoted by step602, missile warning sensors302(FIG. 3) detect the launch and inform controller110, as denoted by steps604and606, respectively. At this point, controller110tracks missile106, as described in further detail below.

FIG. 6Aillustrates the alert aspect of the example method described above. With reference toFIGS. 1A and 1B, after missile warning sensors302(FIG. 3) inform controller110of a missile launch, the controller110informs control tower502(FIGS. 5A–5B) that a missile launch has been detected, as denoted by step614. Control tower502then informs aircraft102to proceed to predetermined position as denoted by step616.

FIG. 6Billustrates the tracking aspect of the example method described above. With reference toFIGS. 1A and 1B, after missile warning sensors302(FIG. 3) inform controller110of a missile launch, controller then receives missile tracking data from turrets304of missile106, as denoted by step620. Controller110receives missile tracking data from suitable fine trackers of turrets304during the entire missile flight (as denoted by step621) and therefore calculates a point of origin and/or a point of impact of missile106. In one embodiment, controller110triangulates missile tracking data received from turrets304to calculate the point of origin and/or point of impact of missile106. Controller110then calculates the point of origin of missile106(or the location of terrorist104), as denoted by step624and alerts security unit504(FIGS. 5A–5B) of the calculated point of origin of missile106, as denoted by step626. Controller110also calculates the point of impact of missile106, using the missile tracking data, as denoted by step628, and alerts response unit506(FIGS. 5A–5B) of the calculated point of impact, as denoted by step630. Additionally, controller110may also alert any other suitable entity, as denoted by step632, of any of the collected information, including the detection of a missile launch, the missile tracking data, the calculated point of impact, and/or the calculated point of origin of the missile launch. The entity may be any group, individual or controller that does not fall into either security unit504or response unit506. In a particular embodiment of the present invention, the entity is a hospital.

Although embodiments of the invention and some of their advantages are described in detail, a person skilled in the art could make various alterations, additions, and omissions without departing from the spirit and scope of the present invention as defined by the appended claims.