Advanced Airborne Defensive Laser for Incorporation on Strike Fighter Aircraft

A technical and operational analysis of an airborne “hard-kill” Ytterbium fiber laser-based anti-missile system for use on strike fighters.

Single Missile Fired at Host Aircraft.

Short-range missiles pose a significant threat to U.S. strike fighters. These missiles are usually small and highly mobile and can be carried on light vehicles and by individual people. Although these missiles do not have a long range, the unpredictability of their launch sites increases their lethality. Also contributing to their lethality are the methods of homing in on their targets. Most are passive methods, such as infrared. Unlike active radar homing, these missiles provide no warning to the aircraft that it is being tracked until the missile has been launched.

The varieties of homing methods for these missiles can also provide problems for aircraft countermeasure systems. Each type of homing method requires a different type of countermeasure. All current airborne countermeasure systems rely on “soft-kill” methods of protection involving confusion or distraction of the homing system. These systems work differently for different homing methods and must be constantly upgraded to protect against ever more complex targeting systems.

A “hard-kill” Advanced Airborne Defensive Laser (AADL) system could use a high-energy laser to either destroy an incoming missile or cause enough physical damage to prevent the missile from intercepting its target. The AADL will be an external pod mounted on a strike fighter and will be almost entirely autonomous. The system will detect missile launch, track targets, and eliminate them. It will use built-in systems for power generation, target tracking, and laser transmission.

The concept of operations (CONOPS) of the system begins with detecting missile launch. The system detects the missile and automatically begins tracking it and plotting a firing solution. Simultaneously, the mission computer of the AADL uses the host aircraft’s communication systems to alert the pilot and friendly forces to the threat. Once a firing solution has been determined and the laser transmitter moved into position, the incoming missile is fired upon and neutralized. This action is taken without input from the pilot as any delay from human reaction time can cause disaster.

After the threat is neutralized, the pilot and friendly forces are once again notified. If there are further incoming missiles, the highest priority threat is targeted and engaged. A set of requirements describing the actions necessitated by the CONOPS in further detail was also developed. Based on these requirements, a functional architecture was created. This architecture breaks those requirements down into a hierarchy of functions and allows, in combination with the physical architecture, creation of an allocated architecture. This physical architecture is a generalized relationship of components based on research into existing systems analogous to the subsystems of the AADL. Following this, an allocated architecture was developed, showing that every function is accomplished by a component.

Research was then conducted into currently existing technology that could be used to develop design alternatives for the AADL. These alternatives consisted of technology for the power supply, laser transmission, and targeting subsystems. These specific subsystems were analyzed because these were the main subsystems whose functions could not be accomplished by technology commonly used by the U.S. military. These technologies were analyzed for cost, effect on flight performance, technology risk, and functional performance. Because of the immature nature of these technologies, the cost could not always be established. Where that information was not available, information on construction materials and methods was used to provide a comparative cost between alternatives.

Effect on flight performance was established by comparing the weights and speed limits of the alternatives. Technology risk was based on the Technology Risk Level standards established by the Department of Defense. Finally, the functional performance was assessed through the use of computer simulations. These simulations use a program named ExtendSim to model the positions and velocities of the aircraft and incoming missiles. This information was then passed to a physics-based high-energy laser modelling program called HELEEOS to determine the amount of time needed to neutralize the missile.

This work was performed by Stephen Cannon, Timothy Kaniss, Nathan Lautzenheiser, Cesar Rios, Greyson Siegel, Jeremy Smith, and Eric Wright for the Naval Postgraduate School. For more information, download the Technical Support Package (free white paper) below.

This Brief includes a Technical Support Package (TSP).
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Advanced Airborne Defensive Laser for Incorporation on Strike Fighter Aircraft

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