Fiber Optic Towed Decoy
Technology is incredible. It allows us to conquer everyday tasks with ease, provides us with entertainment, and even protects our country. The United States is known for its extremely powerful and technologically advanced military. In recent years many strides have been made in terms of bettering our weapons through the addition of new technologies to current ones. A prime example of this is some of the newest technology used by both the navy and air force, the Fiber Optic Towed Decoy (FOTD). Broken down into its most basic form the FOTD is attached to an aircraft by a fiber optic cord to deter radio frequency (RF) lock on missiles, fired by an enemy, from the aircraft and instead lock onto the decoy.
FOTD’s must overcome a couple of objectives in order to be fully functional. The first of these objectives is stability. At high speeds major stresses are placed on these cords that keep the FOTD attached to the aircraft. In order to maintain stability and minimize stress FOTD’s are modified with “distinct dynamic fins.” These “fins adjust to changes in the air stream and help to maintain continuity” throughout the cord. Secondly and lastly, the cord must be able to withstand the immense heat that comes from the exhaust of the powerful F18 afterburners. Through research and testing BAE Systems has been able to develop a “thermally resistant fiber optic line that has withstood more than three times the required duration of exposure in maximum afterburner.” By overcoming these two obstacles the FOTD’s are now able to function without the fear of technical failure and loss.
FOTD’s were designed as a countermeasure to enemy missile fire and designed to improve the survivability of aircrafts. FOTD’s are a part of a category of Integrated Defensive Electronic Countermeasures (IDECM) known as Radio Frequency Countermeasures (RFCM). Aircrafts that carry these RFCM’s have both onboard and off-board (FOTD’s) components to make the aircraft as safe as possible. The countermeasures that these RFCM’s apply are known as jamming. Successful jamming in terms of the FOTD’s “is generated by onboard RFCM equipment and provided to a decoy towed behind the aircraft for amplification and transmission.” The purpose of doing so is to take have enemy radio frequency lock on missiles diverted from its main target, the aircraft, and define and lock onto a new target, the decoy. The transmission of the signal is one of the most interesting parts about the FOTD. The original signal from the aircraft “is converted into light and transmitted down a fiber-optic link to the decoy, at which point the light signal is converted back to a radio frequency, amplified, and transmitted using antennas integral to the decoy.” This is extremely complex engineering at work, let alone the fact that this must all function at high altitudes, speeds, and temperatures.
Warfare is not all about making a weapon more armed or powerful, but sometimes it is making a weapon more evasive and difficult to destroy. That is exactly the task that the FOTD does for aircrafts. By creating a way to increase the longevity and survivability of aircrafts, the FOTD is truly a huge asset to the military.
Fiber Optic Towed Decoy References
http://www.globalsecurity.org/military/systems/aircraft/systems/an-ale-55.htm
http://www.defenseindustrydaily.com/ALE-55-Towed-Fighter-Decoys-for-US-Navy-Australia-05385/
