This paper presents a non-lethal concept using an innovative directed energy pulser for counter-personnel and crowd control. A high power pulsed electrical discharge, initiated using a wire in air, simultaneously generates a loud acoustic report and a bright light pulse. A reflector directs and focuses the 'flash/bang' to deliver high intensity pulses at range. The counter-personnel and crowd control effect is variable through both the intensity of each pulse and the pulse repetition rate. The system can be battery powered, and man portable or mounted on a jeep or other vehicle. This 'air sparker' is different from existing flash-bang approaches which employ a chemical reaction from a 'grenade', and different from laser approaches that generate a plasma in the vicinity of the targeted personnel. A design example using quantitative laboratory measurements, and reflector design and modeling, exhibits the output potential of air sparkers. Using generic non-lethal effects available in the open literature, the design example indicates that air sparker technology may have widespread non-lethal applicability. New sparker technology can lead to compact efficient systems. Development of air sparkers for non-lethal counter-personnel and crowd control should address both the technology and the combined effects.

We have performed analysis of the requirements for an optical dazzler, designed and built a three-wavelength source with a baseline beam projector, and a Smart Beam Projector that can point the beam, and adjust the laser power for a particular target. The source is based on diode lasers, and diode pumped lasers in the Red, Green and Violet ranges of wavelengths. Each laser can be independent adjusted in output power, and pulse duration. The beams are combined using optical fibers, and the source fits in a 1/4 cubic foot Pelican Box, and can run off a battery for field testing. The baseline beam projector can be mounted to a rifle or pistol. The Smart beam projector is designed for laboratory testing at this time. The operation of the prototype system will allow a variety of combinations of laser power, and pulse length to give a varying spatial and temporal profile of illumination. The system is to be tested by the Army for effectiveness. A next generation of dazzler is under construction that will allow microprocessor control of pulse power and duration, increasing the variety of illumination spatial and temporal patterns and more fully utilizing the Smart beam projector capabilities.

Experimental studies on single cells have shown that application of pulsed voltages, with submicrosecond pulse duration and an electric field on the order of 10 kV/cm, causes sudden alterations in the intracellular free calcium concentration, followed by immobilization of the cell. In order to examine electrical stimulation and incapacitation with such ultrashort pulses, experiments on anesthetized rats have been performed. The effect of single, 450 nanosecond monopolar pulses have been compared with that of single pulses with multi-microsecond duration (TASER pulses). Two conditions were explored: 1. the ability to elicit a muscle twitch, and, 2. the ability to suppress voluntary movement by using nanosecond pulses. The second condition is relevant for neuromuscular incapacitation. The preliminary results indicate that for stimulation microsecond pulses are advantageous over nanosecond pulses, whereas for incapacitation, the opposite seems to apply. The stimulation effects seem to scale with electrical charge, whereas the disruption effects don't follow a simple scaling law. The increase in intensity (time of incapacitation) for a given pulse duration, is increasing with electrical energy, but is more efficient for nanosecond than for microsecond pulses. This indicates different cellular mechanisms for incapacitation, most likely subcellular processes, which have been shown to become increasingly important when the pulse duration is shortened into the nanosecond range. If further studies can confirm these initial results, consequences of reduced pulse duration are a reduction in weight and volume of the pulse delivery system, and likely, because of the lower required energy for neuromuscular incapacitation, reduced safety risks.

We assessed the capacity of ultrashort E-fields to activate rat cutaneous nociceptors. Experiments were conducted in vitro on nociceptive neurons representing hairy skin and glabrous skin. Electrical and optical recording methods were used to assess action potentials and membrane damage thresholds. Strength duration (SD) curves were formed for E-field pulses from 500 μsec to 350 ns. There were no differences in the SD time contant (taue (59 μsec) or ultrashort thresholds (129 V/cm at 350 ns) for hairy or glabrous skin nociceptors, for nociceptors with distinct geometry or for nociceptors expressing different combinations of voltage sensitive Na⁺ channels (TTX_s and TTX_r Na_v) or hyperpolarization activated channels (HCN; I_H). Subthreshold activation was possible with high frequency pulsing at ultrashort durations (350 ns; 4,000 Hz). Relative to single pulse thresholds, activation threshold could be reduced over 50% by high frequency burst trains (4,000 Hz; 1-40 msec). Nociceptors were not damaged by E-field activation. Irreversible membrane disruption occurred at significantly higher field strength and varied by cell radius (3,266-4,240 V/cm, 350 ns, 40 Hz, 5 sec). Pulse frequency had no influence on acute membrane failure (10, 20, 40, 4,000 Hz; 5 sec).

Obscurants containing glycols and glycerin, which are widely used in the entertainment industry to produce theatrical effects, are now being used in more concentrated forms in antitheft and riot control. While there have been several studies demonstrating that theatrical fogs are innocuous for humans, the toxicity of the denser fogs has not been examined. In this paper we review the results of previous safety studies of theatrical fog, summarize the effect of increasing concentrations of these obscurants on visibility, and then report on the physiological and biochemical impact of higher concentrations of these obscurants for several hours in rats. Our results suggest that even prolonged exposure to highly obscurant levels of propylene glycol / glycerin fog produces only minimal physiological aftereffects.

We report on the use of a novel phase element to control the far-field intensity pattern generated by a high-peak-power, femtosecond laser. The pre-determined intensity pattern results in a well defined location of the filaments formed by the propagation of these beams through the atmosphere. This enhancement of the localization and repeatability of the intensity distribution can be extremely beneficial for laser induced breakdown spectroscopy (LIBS) of remote regions of interest.

Plasmas produced by laser-matter interactions are a known source of electromagnetic radiation. However, little has been done to systematically study the electromagnetic radiation emitted from laser produced plasmas. It is our intent to provide detailed time and frequency domain measurements of such emitted radiation. An ultra-fast femtosecond high intensity laser and a superheterodyne receiver are employed to study laser-matter interactions for various materials in the frequency range 1-40GHz.

Laser interactions with bulk transparent media have long been investigated for material processing applications involving ablation and shock wave generation in both the nanosecond and femtosecond pulse width regimes¹. Shock waves have been studied in fused silica and other optical glasses but previously have been characterized by the morphology of the concurrent ablation. We perform ablation at distances of 30 meters using the non-linear self-channeling effect. Using silicon wafers as targets because of their clearly defined ablation zones, we examine the effect that the filament has on the thin SiO₂ layer coating the wafer's surface. It is observed that the surface layer experiences a shock wave resulting from the explosive forces produced by the plasma. The use of several laser pulses in burst mode operation leads to the observation of multiple shock fronts in the material, and the possibility of shock wave addition for higher damage. Optical interferometry will be used to characterize the shock wave dynamics, using both traditional means of focusing in the near field and at 30 meters using propagating self-channeled femtosecond pulses. The novelty of using self-channeling laser pulses for shock wave generation has many implications for military applications. These experiments are to be performed in our secure test range using intensities of 10¹⁴W/cm² and higher incident on various transparent media. Interferometry is performed using a harmonic of the pump laser frequency. Experiments also include burst-mode operation, where a train of ultra-fast pulses, closely spaced in time, and novel new beam distributions, strike the sample.

The need for robust, versatile, and rapid analysis standoff detection systems has emerged in response to the increasing threat to homeland security. Laser Induced Breakdown Spectroscopy (LIBS) has emerged as a novel technique that not only resolves issues of versatility, and rapid analysis, but also allows detection in settings not currently possible with existing methods. Several studies have shown that femtosecond lasers may have advantages over nanosecond lasers for LIBS analysis in terms of SNR. Furthermore, since femtosecond pulses can travel through the atmosphere as a self-propagating transient waveguide, they may have advantages over conventional stand-off LIBS approaches¹. Utilizing single and multiple femtosecond pulse laser regimes, we investigate the potential of femtosecond LIBS as a standoff detection technology. We examine the character of UV and visible LIBS from various targets of defense and homeland security interest created by channeled femtosecond laser beams over distances of 30m or more.

The High Altitude Airship (HAA) has various potential applications and mission scenarios that require onboard energy harvesting and power distribution systems. The energy source considered for the HAA's power budget is solar photon energy that allows the use of either photovoltaic (PV) cells or advanced thermoelectric (ATE) converters. Both PV cells and an ATE system utilizing high performance thermoelectric materials were briefly compared to identify the advantages of ATE for HAA applications in this study. The ATE can generate a higher quantity of harvested energy than PV cells by utilizing the cascaded efficiency of a three-staged ATE in a tandem mode configuration. Assuming that each stage of ATE material has the figure of merit of 5, the cascaded efficiency of a three-staged ATE system approaches the overall conversion efficiency greater than 60%. Based on this estimated efficiency, the configuration of a HAA and the power utility modules are defined.

In March 2005, Planning Systems, Inc. (PSI), Advanced Acoustic Concepts (AAC) and the U.S. Army Research Development and Engineering Center (ARDEC) tested the PSI Acoustic Counter Battery System (ACBS) at the Yuma Proving Ground (YPG). ACBS was designed to acoustically detect and locate mortar fire, and to detect and locate heavy artillery fire out to ranges beyond 12 km. During analysis of the test data, we discovered that long-range sensors were receiving multiple pulses in doublets and triplets from a single shot. Additionally, we observed that the leading pulses were arriving earlier than anticipated by surface speed of sound calculations. The analysis team modeled the atmosphere recorded during the test and identified the possible causes of multiple arrivals by modeling the supersonic projectile trajectory and by using Green's Function Parabolic Equation numerical techniques to propagate recorded pulses from the source to receivers. The lessons learned will be applied to adjust the signal processing algorithms in the ACBS. This paper describes the test setup and reports the results of the analysis.

OPTRA presents a new approach to remote infrared temperature measurements over mid to long standoff ranges in varying atmospheric conditions. The sensor is intended as a feedback mechanism for use with the Active Denial System to insure the target's skin temperature is within a safe range. OPTRA's sensor employs a small reflector telescope followed by a series of interference filters which form spatially identical but spectrally separated images on two miniature uncooled microbolometer focal plane arrays. On a pixel by pixel basis, we algebraically combine and normalize the two images. By carefully selecting the spectral passbands of the two images, the mathematical process yields a result that is substantially free of errors caused by humidity, rain, light fog, and atmospheric carbon dioxide. The package measures six x six x 18-inches and weighs six lbs. The package includes an on-axis miniature visible imager, and the graphical user interface presents a fused visible/infrared image with user-defined transparency levels. The visible/infrared combination provides good spatial resolution at large distances and ease of pointing along with the accurate temperature measurement across the field of view.

Aimed at test and evaluation needs on high power microwave (HPM) weapons, we describe new developments on miniature all-dielectric optical field sensors with flat RF sensing response from ~ MHz to 12 GHz, with negligible field perturbation, good sensitivity (~70 mV/(mH√z), and >100dB dynamic range. Present devices use a 20 mm long sensing region in an integrated optical (IO) waveguide Mach-Zehnder interferometer (MZI) using electrooptic (EO) polymer for the waveguide. The fiber-coupled optical transmitter/receiver utilizes common optical communication technology. The incident HPM RF field induces an instantaneous change in the index of refractive of the polymer that is converted into an optical intensity modulation in the MZI device. The poled EO polymer requires no electrodes nor metallic antennas that can distort the field under test. We characterized the frequency response and polarization sensitivity of the field sensor, and both agree well with modeling predictions. Common fabrication limitations result in devices with sensitivity to thermal drift. New sensor designs are being developed with remote bias control that also can provide self-calibration. To further reduce the sensor size and insertion loss, beneficial for array applications, an "in-fiber" field sensor is being developed. The core of a D-shaped fiber is partially removed and replaced with EO polymer. Such a device may use polarization modulation sensing, or be configured in similar MZI structures as the IO waveguide sensors.

Use of force justification, second nature to law enforcement personnel, is increasingly considered by military personnel especially in military operations on urban terrain (MOUT) scenarios. In these situations, military and civilian law enforcement objectives are similar: exert control over individuals and groups with minimum force. Although the list of potential devices and systems grow, empirical demonstrations of effectiveness are lacking. Here, a position is presented regarding approaches to experimental analysis of nonlethal (a.k.a., less-than-lethal and less lethal) technologies and solutions. Appreciation of the concepts of suppression and its attendant behavioral variables will advance the development of nonlethal weapons and systems (NLW&S).

Blunt impact munitions are often used by civilian law enforcement and in military operations on urban terrain (MOUT) missions to dissuade individuals and groups from approaching valued assets. The use of blunt munitions (rubber-ball or sponge) is predicated on their effectiveness as aversive stimuli; the effectiveness is weighed against the risk of serious injury or death. However, little empirical evidence supports effectiveness. Here, we use a paintball gaming context to study the effects of blunt impact on performance and approach behaviors. Volunteers individually traversed a course in which targets offer the opportunity to gain for accuracy. While completing the targeting task, subjects were bombarded with paintballs, which progressively became more numerous and the impact more intense as the subjects neared goal locations. Initial data suggest that over 30 blunt impacts by paintballs delivered at 280 ft/sec over 30 to 100 ft are insufficient to overcome intrinsic and extrinsic approach motivations or impair targeting or advance performance in an overwhelming majority of subjects. Our apparent ceiling effect was surprising. A sub-comparison of the few subjects who stopped the game before the end with those who did not suggests that personality factors influence the effectiveness of blunt impact as a deterrent. While paintballs differ from traditional blunt impact munitions on a number of physical characteristics, impact that was sufficient to repeatedly bruise volunteers was not an effective deterrent.

This paper reviews research conducted by our laboratory exploring the possible use of acoustical stimuli as a tool for influencing behavior. Over the course of several programs, different types of acoustic stimuli have been evaluated for their effectiveness in disrupting targeting, balance, and high-order cognitive processes in both humans and animals. Escape responses are of particular use in this regard. An escape response serves not only as an objective measure of aversion, but as a potential substitute for ongoing behavior. We have also assessed whether the level of performance changes if the individual does not perform an escape response. In general these studies have both suggested certain types of sounds are more aversive or distracting than others. Although the laboratory development of additional stimuli needs to continue, we are taking the next step by testing some of the more effective stimuli in more applied experimental scenarios including those involving group dynamics.

Civilian law enforcement and military operations on urban terrain (MOUT) regularly enter into unknown situations where some unidentified subset of the populace may possess armaments that may be used against them. Ultimately, the most relevant test of the effectiveness of non-lethal energies in these situations is their ability to interfere with the targeting of those weapons on the friendly forces. It is also the test that offers the most immediate and tangible reward in the prevention of personnel injuries. Perceptual interference (e.g., light-induced flash blindness) or distractions from loud noises may contribute to targeting interference. How much do various energies or perceptual interventions actually interfere with targeting? We have devised a program of experimentation that allows for the pure and precise measurement of interference with the targeting process by any of a broad range of energies and stimuli. Our primary focus has been on sound and light interference with targeting, and experiments toward that purpose are described here. As expected, targeting accuracy decreased and targeting latency increased as the distance from fixation point to the target increased. The light flash interfered more with shots at more distant targets. Furthermore, as the angle between the fixation point and the flash increased, targeting latency increased but targeting accuracy was unaffected. Thus, light interference is greatest when the flash is not at the point of fixation. These studies suggest that foveal flashes are less disruptive than peripheral flashes, and that disruption increases as targeting task demands increase.

Training prepares first responders for disasters including terrorist attacks. To train effectively it should be as realistic as possible and elicit the stress response. We are developing a profile that will be a marker for intensity of stress as well as differentiate stress from exertion. We have monitored stress during several training scenarios for different groups including civilian SWAT teams and the military. In addition, we can monitor stress to exposure to nonlethal weapons. We have monitored stress during exposure to blunt impact using a paintball paradigm. We have measured salivary substances (such as cortisol and DHEA [markers for the hypothalamic-pituitary-adrenal axis]) and amylase [marker for the sympathetic branch of the autonomic nervous system], physiological parameters (such as activity and heart rate), and neuropsychological assessment tools (such as Borg's perceived exertion scale, Spielberger's STAI and Thayer's ADC). With these neuroendocrine, physiological and behavioral indices in hand, we are poised to examine stress induction in preparedness in trainees.

Modern simulation techniques have a growing role for evaluating new technologies and for developing cost-effective training programs. A mission simulator facilitates the productive exchange of ideas by demonstration of concepts through compellingly realistic computer simulation. Revolutionary advances in 3D simulation technology have made it possible for desktop computers to process strikingly realistic and complex interactions with results depicted in real-time. Computer games now allow for multiple real human players and "artificially intelligent" (AI) simulated robots to play together. Advances in computer processing power have compensated for the inherent intensive calculations required for complex simulation scenarios. The main components of the leading game-engines have been released for user modifications, enabling game enthusiasts and amateur programmers to advance the state-of-the-art in AI and computer simulation technologies. It is now possible to simulate sophisticated and realistic conflict situations in order to evaluate the impact of non-lethal devices as well as conflict resolution procedures using such devices. Simulations can reduce training costs as end users: learn what a device does and doesn't do prior to use, understand responses to the device prior to deployment, determine if the device is appropriate for their situational responses, and train with new devices and techniques before purchasing hardware. This paper will present the status of SARA's mission simulation development activities, based on the Half-Life gameengine, for the purpose of evaluating the latest non-lethal weapon devices, and for developing training tools for such devices.

The U.S. Coast Guard has identified a need to be able "mark" small vessels from a helicopter or other air asset. Such assets are fuel limited and must frequently break off a contact prior to arrival of boarding teams. Any means of enhancing the target detection range would reduce the number of contacts that are never relocated. It is desired to use existing CG sensors such as NVGs, FLIR or radar. Active devices are easily found and disabled. Consequently passive micro-tags such as luminescent particles (chemical luminescents, dyes, rare earth phosphors, quantum dots), and reflective chaff have been considered. Suitable candidates must be non-toxic, capable of being deployed non-lethally, and difficult to detect or defeat. Laser illuminated IR-reflective chaff has been demonstrated to be detectable at night from a range of five miles. An IR chemical luminescent is also still under consideration. Deployment systems and detection range testing are underway.

Training prepares civilian first responders and military personnel to handle the many aspects of their mission to the best of their capability. For training to be the most effective, it should be as realistic as possible and elicit the stress response. Stress, however, is not measurable by a simple variable or recording. A stress response measurement requires the collection of physiological, behavioral, neuropsychological, and self report variables simultaneously. These are most valid when recorded or documented in real-time to the stress itself. To facilitate the recording of a stress profile, a handheld computer platform (HP-IPAQ) was developed. The HP-IPAQ with the PocketPC operating system running LabVIEW software offers the best flexibility for the interfacing of sensors and physiological amplifiers. The interactive human interface allows for the collection of self-report and other neuropsychological assessments. To test system designs, civilian and military trainees participated in various scenarios. Our system for simultaneous data collection of physiological and behavioral variables shows promise for field applications.

Law enforcement and the military are critically concerned with the targeting and firing accuracy of opponents. Stimuli which impede opponent targeting and firing accuracy can be incorporated into defense systems. An automated virtual firing range was developed to assess human targeting accuracy under conditions of sound and light interference, while avoiding dangers associated with live fire. This system has the ability to quantify sound and light interference effects on targeting and firing accuracy in three dimensions. This was achieved by development of a hardware and software system that presents the subject with a sound or light target, preceded by a sound or light interference. Sony© Xplod.^TM 4-way speakers present sound interference and sound targeting. The Martin ® MiniMAC^TM Profile operates as a source of light interference, while a red laser light serves as a target. A tracking system was created to monitor toy gun movement and firing in three-dimensional space. Data are collected via the Ascension ® Flock of Birds^TM tracking system and a custom National Instrument ® LabVIEW^TM 7.0 program to monitor gun movement and firing. A test protocol examined system parameters. Results confirm that the system enables tracking of virtual shots from a fired simulation gun to determine shot accuracy and location in three dimensions.