Active Denial System FAQs

Q1. Why do we need this technology?
A1.The Active Denial System is needed because it’s the first non-lethal, directed-energy, counter-personnel system with an extended range greater than currently fielded non-lethal weapons. Most counter-personnel non-lethal weapons use kinetic energy (rubber rounds, bean bags, etc.). A kinetic-based system has a higher risk of human injury, and its effectiveness varies in relation to the size, age and gender of the target. The Active Denial System, however, is consistently effective regardless of size, age and gender and has a range greater than small-arms range. The Active Denial System will provide military personnel with a non-lethal weapon that has the same effect on all human targets.

Q2. What type of Department of Defense missions will the Active Denial System support?
A2. The Active Denial System will support a full spectrum of operations ranging from non-lethal methods of crowd control, crowd dispersal, convoy and patrol protection, checkpoint security, perimeter security, area denial, and port protection, as well as other defensive and offensive operations from both fixed-site or mobile platforms. The Active Denial System is an advanced, long-range non-lethal, directed energy, counter-personnel capability that projects a man-sized (1.5 m) beam of millimeter waves (not microwaves) at a range up to 1,000 meters. It will have the same compelling non-lethal effect on all human targets, regardless of size, age and gender. 

Q3. What is the gap between "shout and shoot?"
A3. The Air Force has conducted research on the effects and enabling technologies since the late 1980s. The present ground-based development effort, funded by the Joint Non-Lethal Weapons Program, was initiated in 1997. The Active Denial System was formally designated as an Advanced Concept Technology Demonstration from 2002 to 2007. An Advanced Concept Technology Demonstration is a Department of Defense process to rapidly move mature technologies into the hands of the warfighter for military evaluation.
Q4. What is the status of the Active Denial System program?
A4. The Joint Non-Lethal Weapons Program is continuing to invest in advancing active denial technology to support user interest in a smaller, more mobile configuration for urban environments.

The Joint Non-Lethal Weapons Program and the Army's Research Development and Engineering Command (RDECOM) Armament, Research, Development and Engineering Center (ARDEC) have been collaborating on a next generation Active Denial System that will use solid state technology and yield a smaller, lighter system with a reduction in the start-up time and lower cost. Solid-state active denial technology has the potential to provide a shorter range (~100 m), smaller spot size (~0.5 m) Active Denial System that offers size and weight reductions when compared to the current long range (1000 m), large spot-size systems (1.5 m). Using a gallium nitride semiconductor energy source to produce 95 GHz millimeter waves, solid state Active Denial Technology can be used as a stand-alone "adjunct" system that is integrated onto new or existing platforms.

Q5. Is there more than one Active Denial System?
A5.  Yes. From 2002 to 2007, the Active Denial System Advanced Concept Technology Demonstration integrated and packaged Active Denial Technology into two system configurations. System 1, the technology prototype, integrated the technology into a High Mobility Multi-Purpose Wheeled Vehicle. System 2 was built as an armored, containerized system transportable by tactical vehicles. Both systems successfully completed a series of land and maritime-based military utility assessments. In 2014-2015 System 1 was refurbished into a more robust and mobile system transported by a Marine Corps MTVR truck.

Both prototypes are long range, large spot sizes systems and are available for Service or Combatant Command exercises and are suitable for operational employment. 

Q6. Is The Active Denial System going to deploy any time soon?
A6.  Both prototype systems successfully completed a series of land and maritime-based military utility assessments. Both systems are available for Service or Combatant Command exercises and are suitable for operational employment. If an operational user request is  received, a plan is in place to deploy the system, train operators,  and provided operational support through a field-service  representative.

Q7. Is Active Denial System a laser?
A7. The Active Denial System is not a laser and does not employ a laser as its source of directed energy. The source for the Active Denial System energy is a gyrotron, which uses entirely different physics to generate the electromagnetic energy beam directed from the Active Denial System. The Active Denial System generates a focused and very directional millimeter-wave radio frequency beam. There is an eye-safe laser range finder associated with the system for range determination.

Q8. Is the beam radioactive?
A8. No. The beam is not radioactive, nor does the Active Denial System beam have radioactive materials associated with it.

Q9. Does this system work like a microwave oven?
A9.  No. The ADS, a non-lethal directed-energy weapon, projects a very short duration (on the order of a few seconds) focused beam of millimeter waves at a frequency of 95 gigahertz (GHz). A microwave oven operates at 2.45 GHz. At the much higher frequency of 95 GHz, the associated directed energy wavelength is very short and only physically capable of reaching a skin depth of about 1/64 of an inch. A microwave oven operating at 2.45 GHz has a much longer associated wave length, on the order of several inches, which allows for greater penetration of material and efficiency in heating food. The ADS provides a quick and reversible skin surface heating sensation that does not penetrate into the target. 

Q10. How do you know it is safe?
A10. An extensive research program was undertaken to understand the effects of the Active Denial System on the human body. The goal was to ensure that the effects of millimeter waves are well understood and that a wide safety margin exists between operationally useful levels of effects and those that may cause injury.

More than 15 years of research more than 13,000 exposures from volunteers, both in static demonstrations and in realistic operational assessments, demonstrate effectiveness and minimal risk of injury. The Air Force Research Laboratory's Human Effectiveness Directorate at Brooks City-Base, Texas, conducted many years of successful and safe laboratory testing. In 2000, testing began at Kirtland Air Force Base, south of Albuquerque, N.M., using a full-scale Active Denial Technology hardware demonstrator. A formal institutional Review Board reviewed and approved all testing with oversight from the Air Force Surgeon General's Office.

Adverse reactions are extremely rare, temporary and consist of skin blisters. Exposure to the Active Denial System can also result in a temporary reddening of the skin. Research shows there is only a 1/10th of 1% chance of injury from Active Denial System exposure. Normal, innate, self-protect behaviors such as eye blink, head turn and aversion response all minimize the risk of injury. The energy reaches a skin depth of only about 1/64th of an inch, the equivalent of three sheets of paper. The sensation immediately ceases when the individual moves out of the beam.

These findings have undergone six independent reviews. Throughout the research program, the Human Effects advisory Panel, an independent panel of non-government science and medical experts, also periodically reviewed and advised on the planning aspects and results of the research and test activities. In a 2008 review of the program, this panel concluded that there is low risk of serious injury from exposure to the Active Denial System beam. A copy of the panel's report can be found here

Q11. Have there ever been any injuries associated with the Active Denial Systems?
A11. Yes. There have been two injuries associated with Active Denial System exposures that have required medical attention. They were both second-degree burns. The first incident occurred in January 1999 and stemmed from a laboratory mishap. The incident resulted in a quarter-size blister and necessitated only outpatient care. The second mishap occurred in April 2007, in which an Airman was injured during a training exercise at Moody AFB, GA. The Airman received second-degree burns (blisters) from an overexposure to the Active Denial System due to procedural errors. The Airman made a full recovery and returned to active duty. In an effort to minimize the risk of injury, changes were made to the engagement procedures, the procedural checklists and the training processes to Active Denial System controls. Additionally, a multiple-person validated compliance process and a software upgrade were incorporated. Research shows that there is only a 1/10th of 1% chance of injury associated with exposure to Active Denial Systems.
Q12. Who participated in the testing?
A12. More than 13,000 volunteers have participated in the Active Denial System testing, including active duty military, reserve military, retired military and Department of Defense civilians. All testing strictly adheres to the procedures, laws and Federal regulations governing human research. The tests involving humans have been reviewed by an Institutional Review Board composed of a diverse group of qualified experts. Beyond the reviews conducted at the local level, research proposals are extensively reviewed by special committees at the Air Force Research Laboratory and at the office of the Air Force Surgeon General. Humans participating in this research must be true volunteers. Each volunteer must read and sign a detailed voluntary consent form before participation. Copies of the blank consent form are available for review. The forms are drafted in compliance with 32 CFR Section 219 and Air Force Instruction 40-402. Solicitation of volunteers occurred by word of mouth. We have had no trouble getting enough volunteers.

Q13. What safeguards does the system have to prevent misuse of the Active Denial System?
A13. The Active Denial System incorporates many levels of control to ensure a safe and effective repel effect. The hardware in the system includes a bore-sighted sensor suite that allows the operator to see the entire beam path and target area and requires no adjustments for ballistics or wind. The Active Denial System also incorporates computer systems that limit shot duration. In addition, changes to engagement procedures, software upgrades, improved checklists, multiple-person validated compliance and enhanced training processes to Active Denial System controls have been incorporated to minimize the chance of injury. 

Q14. Can this technology ever be lethal?
A14. The Active Denial System was specifically designed as a non-lethal weapon. For this technology to become lethal, the energy beam exposure would have to be sustained and prolonged many times over the duration required to achieve the repel effect. The Active Denial System incorporates many levels of control to ensure a safe and effective repel effect. The hardware in the system allows the operator to see the entire beam path and target area and requires no adjustments for environmental factors such as wind. In addition, changes to engagement procedures, software upgrades, improved checklists, multiple-person validated compliance and enhanced training processes to Active Denial System controls have been incorporated to minimize the chance of injury.
Q15. Does the Active Denial System cause cancer or affect fertility?
A15. No. Detailed human effects research has been conducted. We have done testing to determine whether or not short-term and repeated exposure to this millimeter-wave energy may cause cancer. The results show that there is no risk of cancer for either the system operator or the targeted individual. We are very confident in this, and the independent review boards agree. A detailed report of the study appears in the peer review journal, Carcinogenesis (2001) 22: 1701-1708. Similar studies regarding fertility have recently been completed. Because the energy reaches a depth of only about 1/64th of an inch, the energy cannot affect reproductive organs. Experimental results showed no detrimental effects.

Q16. Is the beam more powerful, or possibly lethal, within a short distance of the antenna?
A16.  No. While the intensity of the beam varies somewhat with range, the safety margin and effects calculations have taken the maximum beam intensity into account. The repel effect will be virtually identical at short or long ranges until the effects dissipate beyond the system’s effective range.

Q17. What does exposure to the Active Denial System feel like?
A17. Many volunteer test participants liken the effect to the temporary heat felt from opening the door to a hot oven. The sensation dissipates when the target moves out of the beam. The sensation is intense enough to cause a nearly instantaneous reflex action of the target to flee the beam.

Q18. The Active Denial System hits you directly in the eye, will it blind you?
A18. No. We have conducted extensive studies on whether Active Denial System can affect the eyes. The studies have all shown that natural blink reflex, aversion response and head turn all protect the eyes. The Air Force Research Laboratory has performed research proving that eyeglasses, contact lenses, binoculars and night vision goggles do not increase the risk of eye injury from Active Denial System exposure. More information is available on page 13 of the Human Effects Advisory Panel report.

Q19. Is exposure to the Active Denial System harmful to subjects wearing jewelry, coins, glasses or metal?
A19. No. There are no adverse effects to subjects who are wearing any of these items.

Q20. Is the Active Denial System legal?
A20. Yes. The technology has undergone a full legal and treaty review and has been found to be compliant with the international legal obligations of the United States. These legal obligations include the law of war treaties and arms control agreements to which the United States is a party, customary international law, domestic law and U.S. policy. These reviews have determined there are no legal prohibitions to the development and use of this technology when it is employed properly and in accordance with appropriate tactics, techniques and procedures.

Q21. Are you sure there won’t be adverse effects years from now?
A21. As a result of the extensive human effects research completed on the Active Denial System, we are very confident there will be no long-term adverse side effects. Numerous valid scientific studies have shown no link between energy in this region of the electromagnetic spectrum and adverse health effects. Human effects studies related to exposure to the technology associated with the Active Denial System include the following:

Chalfin, S., D’Andrea, J.A., Comeau, P.D., Belt, M.E., and Hatcher, D.J. Millimeter wave absorption in the nonhuman primate eye at 35 GHz and 94 GHz. Health Physics, 83(1): 83-90, 2002.

Foster, K.R., D’Andrea, J.A., Chalfin, S., and Hatcher, D.J. Thermal modeling of millimeter wave damage to the primate cornea at 35 GHz and 94 GHz. Health Physics, 84(6): 764-769, 2003.

Jauchem, J.R. A Literature Review of Medical Side Effects from Radiofrequency Energy in the Human Environment. Journal of Microwave Power and Electromagnetic Energy, 32 (2): 103-124, 2003.

Jauchem, J.R. Ryan, K.L., and Frei, M.R. Cardiovascular and thermal responses in rats during 94GHz irradiation. Bioelectromagnetics 20:264-267, 1999.

Mason, P.A., Walters, T.J., DiGiovanni, J., Beason, C.W. Jauchem, J.R., Dick, J.E., Mahajan, K., Dusch, S.J., Shields, B., Merritt, J.H., Murphy, M.R., and Ryan, K.L. Lack of effect of 94-GHz radio frequency radiation exposure in an animal model of skin carcinogenesis. Carcinogenesis 22: 1701-1708, 2001.

Nelson, D.A., Walters, T.J., Ryan, K.L., Emerton, K.B., Hurt, W.D., Ziriax, J.M., Johnson, L.R., and Mason, P.A., Inter-species extrapolation of skin heating resulting from millimeter wave irradiation: modeling and experimental results. Health Physics, 84(5): 608-615, 2003.

Nelson, D.A., Nelson, M.T., Walters, T.J., and Mason, P.A. Skin heating effects of millimeter wave irradiation: Thermal modeling results. IEEE Transactions on Microwave Theory and Techniques 48:2111-2120, 2000.

Pakhhomov, A.G., Akyel, Y., Pakhomova, O.N., Stuck, B.E., and Murphy, M.R. Current state and implications of research on biological effects of millimeter waves. Bioelectromagnetics 19:393- 413, 1998.

Ryan, K.L., D’Andrea, J.A. Jauchem, J.R., and Mason, P.A. Radio frequency radiation of millimeter wavelength: Potential occupational safety issues relating to surface heating. Bioelectromagnetics 78: 170-181, 2000.

Walters, T.J., Ryan, K.L., Nelson, D.A., Blick, D.W., and Mason, P.A., Effects of blood flow on skin heating induced by millimeter wave irradiation in humans. Health Phys. 86(2): 115- 120, 2004.

Walters, T.J., Blick, D.W., Johnson, L.R. Adair, E.R., and Foster, K.R. Heating and pain sensations by millimeter waves: Comparison to a simple thermal model. Health Physics 78:259- 267, 2000.