This PDF file contains the front matter associated with SPIE Proceedings Volume 6540, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Homeland Security R&D budgets will be summarized with an emphasis on the FY 2007 and comparisons to FY 2006 and the proposed FY 2008 budget. A summary of the federal budget process is given with insights into the specific omnibus bill funding FY 2007 for most of the federal budget and the omnibus bill's impact on organizations included in the American Competitiveness Initiative. Projections for FY 2008 Homeland Security Research, as analyzed by AAAS, show that ~80% of R&D funding is outside the Department of Homeland Security. An overview of the conference includes insights into the Drinking Water Security, Border Security, Transportation Security (including an update from the MANPADS program office), Port and Harbor Security, Health Security, and Non-Intrusive Inspection Technologies sessions.

The interest in on-line water quality monitors has increased significantly in the last years, because of the need for rapid, reliable and continuous monitoring. This has resulted in the introduction of new monitors which can provide (near) real-time information on water quality. They can be used for continuous river water quality control as well as for drinking water protection against intentional contamination. Still no universal monitor is yet available which is able to protect against all kinds of threats. The combination of complementary systems into a single integrated monitoring platform would greatly enhance the applicability of real time monitoring devices. Such a combination should be found in the complementary information derived from a chemical analytical technique and from an effect monitor (biomonitor). Where a chemical analytical monitoring system identifies and quantifies specific water contaminants, biomonitoring gives an indication of the total quality, including the effects of unknown toxic substances. This combination was found in using the TOXcontrol, a biological toxicity monitor using luminescent bacteria, and the scan spectroyser^TM, a submersible UV-VIS spectrophotometer probe, to evaluate drinking water safety. This combination allows for the verification of alarm signals from one instrument with the signal of the other, reducing false alarm rates. Experiments were performed in a laboratory setting and in a field test. It is concluded that the combination of the UV-VIS spectrophotometer and the toxicity biomonitor comprises a monitoring system with a high added value being capable of detecting a broad range of contaminants at low concentrations.

A change in the motility pattern of fish and aquatic invertebrates when initially exposed to a toxin has long been used in tests designed to signal the presence of toxins in effluents and receiving waters. We have discovered that the level of motility change occurring within 2.5 hours of exposure to all concentrations of a test toxicant correlates well with mortality observed after three days exposure to the toxin, but that the first 30 minutes of exposure is a poor predictor of mortality. Defining this 'best to use exposure time' can increase the sensitivity of toxicity monitoring systems to a weak toxin, one that causes a motility change so minor that it may otherwise go unnoticed. Motility is monitored and automatically recorded using a Nectophotometer, an automated bio-monitor with computer interface that senses interruptions of infrared beams when organisms separately exposed to multiple concentrations of a toxin move through the beams. In our tests changes in the motility of Artemia salina within the first 2.5 hours of exposure predict 3 day mortality with an average accuracy of 89%. The Nectophotometer has promise for allowing rapid assessment of the toxicity to invertebrates and fish, and may also be used to assess airborne toxicity if motile insects respond in a similar manner.

Ensuring safe water supplies requires continuous monitoring for potential poisons and portable analyzers to map distribution in the event of an attack. In the case of chemical warfare agents (CWAs) analyzers are needed that have sufficient sensitivity (part-per-billion), selectivity (differentiate the CWA from its hydrolysis products), and speed (less than 10 minutes) to be of value. We have been investigating the ability of surface-enhanced Raman spectroscopy (SERS) to meet these requirements by detecting CWAs and their hydrolysis products in water. The expected success of SERS is based on reported detection of single molecules, the one-to-one relationship between a chemical and its Raman spectrum, and the minimal sample preparation requirements. Recently, we have developed a simple sampling device designed to optimize the interaction of the target molecules with the SERS-active material with the goal of increasing sensitivity and decreasing sampling times. This sampling device employs a syringe to draw the water sample containing the analyte into a capillary filled with the SERS-active material. Recently we used such SERS-active capillaries to measure 1 ppb cyanide in water. Here we extend these measurements to nerve agent hydrolysis products using a portable Raman analyzer.

Unmanned ground vehicle technology with integrated EO-IR Sensors and payloads play a key role in border surveillance and security. In recent years, unmanned ground vehicle such as iRobot's PackBot have been a critical tool in providing situational awareness to combat terrorist operations around the world. There is increased recognition of the importance of unmanned ground vehicles with sensor suites as a force multiplication for the infantry and special forces units in future combat or reconnaissance missions and perimeter and border security and first responders. They function as the "eyes, ears, and hands" of the unit and can be remotely deployed without placing the observer's unit in harm's way in risky environments. Evolving unmanned ground vehicle technology produces significantly lighter, more maneuverable, greater endurance UGVs with improved EO, IR and other sensors for reconnaissance, surveillance and situational awareness. They dramatically reduce the risk for soldiers in MOUT operations, relay evidence of booby traps, hidden enemy, and other dangers in caves, tunnels, buildings, vehicles and other areas where the soldier(s) may be at risk. They have expanded mobility in debris fields, stairs, and rugged terrain with IR and visible video and audio links. New sensor technology enables new tactics to be developed and tethers allow secure operation. These UGVs are extremely rugged withstanding the harshest military use. They have high reliability as demonstrated in operations in Afghanistan and Iraq. They are easy to operate with a short set-up time and battery change out time of less than one minute.

Remote detection of radiation is a difficult problem due to the 1/r² fall-off. Recent advances in polymer research and nanoscale fabrication methods along with advances in optical polarimetric remote sensing systems suggest a solution. The basic device uses a micro-wiregrid infrared polarizer fabricated in conductive polymer. When the polymer is exposed to hard radiation, its conductivity will be affected and the polarization properties of the device will change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. We will report on the development of a radiation-sensitive passive dosimeter polymer with very low optical visibility. Progress on material development, lithographic fabrication and optical characterization will be presented.

This paper describes True-Color Night Vision cameras that are sensitive to the visible to near-infrared (V-NIR) portion of the spectrum allowing for the "true-color" of scenes and objects to be displayed and recorded under low-light-level conditions. As compared to traditional monochrome (gray or green) night vision imagery, color imagery has increased information content and has proven to enable better situational awareness, faster response time, and more accurate target identification. Urban combat environments, where rapid situational awareness is vital, and marine operations, where there is inherent information in the color of markings and lights, are example applications that can benefit from True-Color Night Vision technology. Two different prototype cameras, employing two different true-color night vision technological approaches, are described and compared in this paper. One camera uses a fast-switching liquid crystal filter in front of a custom Gen-III image intensified camera, and the second camera is based around an EMCCD sensor with a mosaic filter applied directly to the sensor. In addition to visible light, both cameras utilize NIR to (1) increase the signal and (2) enable the viewing of laser aiming devices. The performance of the true-color cameras, along with the performance of standard (monochrome) night vision cameras, are reported and compared under various operating conditions in the lab and the field. In addition to subjective criterion, figures of merit designed specifically for the objective assessment of such cameras are used in this analysis.

Modern surveillance and security systems demand a technological approach because only technology can provide highly efficient vigilance, a certainty of detection and a fast response 100% of the time. Recent developments, including new wide-angle lenses, advanced cameras, IP networks and video analysis technology, provide significant improvements in system performance and flexibility. This paper presents a new advanced surveillance system featuring a panoramic Panomorph lens for event detection, recognition and identification over a 360-degree area with 100% coverage. This innovative approach provides enhanced performance with better pixel/cost ratio. Intelligent video technology enables the video camera to be "more" than just a video camera; it allows the panoramic image to follow events (such as moving objects or unauthorized behavior) in real time, which in turn allows the operator to focus his/her activity on a narrow field pan/tilt camera without losing any information in the field. Adding incremental capabilities such as a Panomorph lens-based imager to an existing surveillance video system can provide improvements in operational efficiency and effectiveness. Foreseen applications are in the fields of border surveillance, high-security environments, aerospace and defense, mass transit, public security and wherever the need for total awareness is a prerequisite.

Advances in infrared sensors, as well as integrated controls and displays have led to mature designs being incorporated in civil as well as military surveillance and security systems. Technical challenges arise in applying electro-optical sensor technology to detect, track and identify individuals and to detect contraband and hidden objects; while at the same time providing positive cost/benefit metrics for both point protection and area surveillance applications. The previous paper, "EO/IR Sensors Enhance Border Security" addressed the advantages and disadvantages of specific electro-optical sensor modalities, including visible, near-, mid- and far-infrared as well as ultraviolet that may be used individually and in combination to perform specific security applications. System designs employing electro-optical and infrared sensors for surveillance applications were reviewed as well as the cost/benefit metrics used to define trades for both point protection and area surveillance applications. This paper will address the use of these infrared modalities with advanced image and sensor processing developed by Opgal specifically for border security applications.

BAE Systems led a collaborative study with New Mexico State University to investigate a series of ground based persistent surveillance solutions for potential use along the Southwest border of the United States. This study considered a wide range of system options for mobile and fixed site applications. This paper summarizes the findings of the study including the central role of the imaging subsystems in mobile ground based surveillance solutions and the suitability of uncooled IR Microbolometers within this subsystem. The paper also provides a discussion of the benefits of real time decision support applications when fielding a persistent surveillance solution.

With the purpose to increase a level of protection of the important documents, securities, industrial goods, etc. from counterfeiting the polarization-holographic system of protection is developed. The suggested approach is based on new physical principles and allows a level of protection against counterfeiting to be increased. The technology of obtaining protective elements and also a device for the definition of authenticity of these elements has been developed. The suggested system of protection uses specially synthesized polarization-sensitive materials and polarization-holographic elements with special properties. The definition of authenticity is made by means of the analysis of the polarization state of light diffracted on the protective element. The essential advantage of this system is that the copying of polarization-holographic protective element by optical methods is impossible in principle which complicates their counterfeiting.

The latest events of ground-to-air Man Portable Air Defense (MANPAD) attacks against aircraft have revealed a new threat both for military and civilian aircraft. Consequently, the implementation of protecting systems (i.e. Directed Infra Red Counter Measure − DIRCM) in order to face IR guided missiles turns out to be now inevitable. In a near future, aircraft will have to possess detection, tracking, identification, targeting and jamming capabilities to face MANPAD threats. Besides, Multiple Missiles attacks become more and more current scenarios to deal with. In this paper, a practical example of DIRCM systems under study at SAGEM DEFENSE & SECURITY Company is presented. The article is the continuation of a previous SPIE one. Self-protection solutions include built-in and automatic locking-on, tracking, identification and laser jamming capabilities, including defeat assessment. Target Designations are provided by a Missile Warning System. Targets scenarios including multiple threats are considered to design systems architectures. In a first step, the article reminds the context, current and future threats (IR seekers of different generations...), and scenarios for system definition. Then, it focuses on potential self-protection systems under study at SAGEM DEFENSE & SECURITY Company. Different strategies including target identification, multi band laser and active imagery have been previously studied in order to design DIRCM System solutions. Thus, results of self-protection scenarios are provided for different MANPAD scenarios to highlight key problems to solve. Data have been obtained from simulation software modeling full DIRCM systems architectures on technical and operational scenarios (parametric studies).

The use of expendable countermeasures is still found to be a viable choice for self protection against Man Portable Air Defense Systems (MANPADS) due to their simplicity, low cost, flexibility, recent improvements in decoy technology, the ability to handle multiple threats simultaneously and the off-board nature of these countermeasures. In civil aviation, the risk of general hazards linked to the use of pyrotechnics is the main argument against expendable countermeasures, whereas for military platforms, the limitation in capacity due to a limited number of rounds is often used as an argument to replace expendable countermeasures by laser-based countermeasures. This latter argument is in general not substantiated by modelling or figures of merit, although it is often argued that a laser based system allows for more false alarms, hence enabling a more sensitive missile approach warning system. The author has developed a model that accounts for the statistical effects of running out of expendable countermeasures during a mission, in terms of the overall mission survival probability. The model includes key parameters of the missile approach warning system (MAWS), and can handle multiple missile types and missile attack configurations, as well as various statistical models of missile attacks. The model enables quantitative comparison between laser based and expendable countermeasures, but also a dynamic optimization of the countermeasures in terms of whether to use small or large countermeasure programs, as well as the dynamic tuning of MAWS key parameters to optimize the overall performance. The model is also well suited for determination of the contributions of the different components of the system in the overall survival probability.

In the operational airport environment, the rapid identification of potentially hazardous materials such as improvised explosive devices, chemical warfare agents and flammable and explosive liquids is increasingly critical. Peroxide-based explosives pose a particularly insidious threat because they can be made from commonly available and relatively innocuous household chemicals, such as bleach and hydrogen peroxide. Raman spectroscopy has been validated as a valuable tool for rapid identification of chemicals, explosives, and narcotics and their precursors while allowing "line-of-sight" interrogation through bottles or other translucent containers. This enables safe identification of both precursor substances, such as acetone, and end-products, such as TATP, without direct sampling, contamination and exposure by security personnel. To date, Raman systems have been laboratory-based, requiring careful operation and maintenance by technology experts. The capital and ongoing expenses of these systems is also significant. Recent advances in Raman component technologies have dramatically reduced the footprint and cost, while improving the reliability and ease of use of Raman spectroscopy systems. Such technologies are not only bringing the lab to the field, but are also protecting civilians and security personnel in the process.

Establishing a Virtual Sea Border by performing a real-time, satellite-accessible Internet-based bio-metric supported threat assessment of arriving foreign-flagged cargo ships, their management and ownership, their arrival terminal operator and owner, and rewarding proven legitimate operators with an economic incentive for their transparency will simultaneously improve port security and maritime transportation efficiencies.

Stevens Institute of Technology has established a new Maritime Security Laboratory (MSL) to facilitate advances in methods and technologies relevant to maritime security. MSL is designed to enable system-level experiments and data-driven modeling in the complex environment of an urban tidal estuary. The initial focus of the laboratory is on the threats posed by divers and small craft with hostile intent. The laboratory is, however, evolvable to future threats as yet unidentified. Initially, the laboratory utilizes acoustic, environmental, and video sensors deployed in and around the Hudson River estuary. Experimental data associated with boats and SCUBA divers are collected on a computer deployed on board a boat specifically designed and equipped for these experiments and are remotely transferred to a Visualization Center on campus. Early experiments utilizing this laboratory have gathered data to characterize the relevant parameters of the estuary, acoustic signals produced by divers, and water and air traffic. Hydrophones were deployed to collect data to enable the development of passive acoustic methodologies for maximizing SCUBA diver detection distance. Initial results involving characteristics of the estuary, acoustic signatures of divers, ambient acoustic noise in an urban estuary, and transmission loss of acoustic signals in a wide frequency band are presented. These results can also be used for the characterization of abnormal traffic and improvement of underwater communication in a shallow water estuary.

The Houston Ship Channel (HSC) is a 50-mile long shipping channel that contains many private ports including the Port of Houston Authority. It has a uniquely critical role with respect to the US petroleum energy supply. The HSC security is currently planned for significant enhancement under the auspices of the Harris County and the Houston-based Port Strategic Security Council. The ultimate objective is to comprehensively address the HSC threat matrix. This paper describes the technical effort in support of this program. The HSC security is a complex system of systems that includes the physical control access system, the command, control, communication, and information (C4I) system, and the telecom infrastructure. The strategy is to coordinate the improvements of different components to achieve a high-impact net effectiveness. A key element is a planned high-capacity backbone optical network for integrating the C4I of many different HSC administrative-jurisdictional authorities, which will allow unified situational awareness for a more effective cooperation and coordination. Enhancement of surveillance and intrusion protection is crucial. A feasibility study was conducted for the HSC assuming common surveillance technologies including visible/IR camera, radar, and sonar. The method includes survey and theoretical modeling to detect threats of concern in the HSC natural environment. The result indicates that the HSC unique river-like geography offers both advantages and challenges. The narrow channel allows ease of waterside surveillance, but likely incurs high cost for its great length. In addition, landside security is also important owing to its location amidst urban-industrial zone. Lastly, limitation of the various technologies is discussed by considering the broader challenges of the intrusion problem.

In response to a serious homeland security threat exemplified by chemical plants with on-site stores of dangerous substances, rendered vulnerable by their locations on public waterways, we have developed and described a viable approach to persistent optical surveillance for detecting and assessing attacking adversaries sufficiently early to permit probable interdiction by a responding guard force. Last year we outlined the technical challenges and described some of the attributes, of a "smart camera system" as a key part of the overall security solution. We described the relative strengths and weaknesses of various sensors as well as the benefits of software systems that add a degree of intelligence to the sensor systems. In this paper we describe and elaborate the actual hardware and software implementation and operating protocols of this smart camera system. The result is a modular, configurable, upgradeable, open architecture, night-and-day video system that is highly capable today and able to grow to expanded capability in the future.

The presence of Underwater Unexploded Ordnance (UUXO) represents a considerable threat in the marine environment. Elevated concentrations of dissolved explosive compounds, such as TNT and RDX, may be produced in the vicinity of degraded UUXO shell casings and are known to have significant toxicant effects on local marine organisms. During World War II and in subsequent years, the US military inadvertently or, in some cases intentionally, deposited many thousands of tons of UUXO in US coastal waters. Much of this material is difficult to locate by magnetometry or sonar imaging techniques, and can be extremely challenging to identify by visual means after lying on the bottom of the ocean for several decades. The present work is focused on advances in underwater olfaction, wherein trace amounts of dissolved explosive compounds may be detected and discriminated from other chemical species found in the marine environment, for the purpose of establishing safe cordons and/or neutralization of the explosives. ICx Nomadics has developed the first known real-time sensor system that is capable of detecting chemical signatures emanating from underwater explosives. The SeaPup sensor, which is based on the fluorescence-quenching transduction mechanism of an amplifying fluorescent polymer (AFP), is capable of real-time detection of the trace chemical signatures emanating from submerged explosive compounds. The SeaPup system has been successfully tested on various marine platforms, including a crawler robot, an autonomous underwater vehicle (AUV), and a remotely operated underwater vehicle (ROV). In one study, the SeaPup was shown to effectively map liquid phase "explosive scent plumes" emanating from an underwater source of TNT. The presented paper will provide an overview of the history, current status, and future development of explosive analyte detection in the underwater environment.

A new approach for microelectromechanical systems (MEMS) hydrophones is discussed, which yields miniature, low power, and high performance hydrophones. The prototype devices use a laser interferometer with integrated low power electronics built on conventional silicon on sapphire (SOS) complimentary metal oxide semiconductor (CMOS) technology to optically detect pressure waves. Results show sensitivities of -143 dBV re 1 μPa, comparable to or better than piezoelectric, capacitive condenser, or other optical approaches. The implication is to make very low cost hydrophones while drastically reducing the power and computational requirements. This is viewed as a disruptive technology for areas such as coastal defense and port security where cost, size and power consumption is key.

One of the technological challenges associated with trace vapor detection of explosive materials are the relatively low vapor pressures exhibited by most energetic materials under ambient conditions. For example, the vapor pressure for TNT is ~10 ppbv at room temperature, a concentration near the Limit of Detection for many of the technologies currently being deployed. In the case of improvised explosive devices, the clandestine nature of the device further serves to exacerbate the vapor pressure issue. Interestingly, the gold standard in explosives detection remains the trained canine nose. While there is still some debate as to what the dog actually smells, recent studies have indicated the alert response is triggered, not by the vapor presence of a specific explosive compound but, by a characteristic bouquet of odors from chemical impurities used to manufacture and process the explosives. Here we present high resolution infrared data for several of these volatile organic compounds in the 700 cm^-1 region required for real time optical sensing of energetic materials.

Encouraging results are presented for the automatic analysis of radiographic images of a continuous stream of ISO containers to confirm they are truly empty. A series of image processing algorithms are described that process real-time data acquired during the actual inspection of each container and assigns each to one of the classes "empty", "not empty" or "suspect threat". This research is one step towards achieving fully automated analysis of cargo containers.

Deriving water constituents: water clarity, turbidity, bottom type and depth from remote sensing continue to be a challenge in coastal waters. Because relatively large regions can be observed in a short amount of time, the development of data integration techniques to combine multiple elements from satellite and airborne sensors (i.e.: AVIRIS, Hyperion, EOS, MODIS and NPOESS) is highly desirable. Proficient implementation is also multifaceted. As concerns for homeland security have elevated to higher priority, characterization of littoral domains has moved from being driven by environmentally sensitive issues to politically vital matters. In the vulnerable transitional area between ocean and land there exists a void of defined parameters, confident characterization and reliable strategies for operational analysis. This paper surveys traditional optical and photonic techniques for the classification of maritime features, predominantly in the 0 to 100 meter depth range. We discuss the most recent methods and compare them by water depth and practicality as well as present the inherent physical limitations and constraints. The research presented here updates the ocean community and apprises security managers of the primary issues in using satellite and airborne data in littoral zones and suggests perfunctory paths for immediate innovation based on available techniques. This field has great opportunity for breakthroughs in technology such as the NGST "OnePicture Workstation" providing useful information for critical decision making. This work provides an overview of this emerging technology designed to benefit harbor defense/port security as well as promising strategies using data fusion, LUT, higher-dimensional analysis and new visualization techniques.

The paper describes the design and development of a network of wireless gamma-ray sensors based on cell phone or WiFi technology. The system is intended for gamma-ray detection and automatic identification of radioactive isotopes and nuclear materials. The sensor is a gamma-ray spectrometer that uses wireless technology to distribute the results. A small-size sensor module contains a scintillation detector along with a small size data acquisition system, PDA, battery, and WiFi radio or a cell phone modem. The PDA with data acquisition and analysis software analyzes the accumulated spectrum on real-time basis and returns results to the screen reporting the isotopic composition and intensity of detected radiation source. The system has been programmed to mitigate false alarms from medical isotopes and naturally occurring radioactive materials. The decision-making software can be "trained" to indicate specific signatures of radiation sources like special nuclear materials. The sensor is supplied with GPS tracker coupling radiological information with geographical coordinates. The sensor is designed for easy use and rapid deployment in common wireless networks.

Once the presence of the anomaly on the bottom of the shallow coastal sea water is confirmed it is necessary to establish if it contains explosive charge. This could be performed by using neutron sensor installed within an underwater vessel - "surveyor". When positioned above the object, or to its side, the system inspects the object for the presence of the explosive by using neutrons from the sealed tube d+t neutron generator. In order to evaluate various components and geometries a test basin containing sea water and sand was constructed. Components of the neutron sensor were placed inside a waterproof stainless steel box which could be moved up and down inside the basin. Measurements were performed by neutron generators with and without detection of associated alpha particles. Low energy resolution gamma detectors (BGO and NaI) were used. The sensor using neutron generator with detection of associated alpha particles was found to have a superior performance since the detection of alpha particles defines the neutron beam which helps the reduction of the background. The most common military explosives are characterized by H, C, N, O concentration values. Whole spectrum signature could be used for the identification of the materials investigated.

Terrorists intent on causing many deaths and severe disruption to our society could, in theory, cause hundreds to tens of thousands of deaths and significant contamination of key urban facilities by using chemical or biological (CB) agents. The attacks that have occurred to date, such as the 1995 Aum Shinrikyo CB attacks and the 2001 anthrax letters, have been very small on the scale of what is possible. In order to defend against and mitigate the impacts of large-scale terrorist attacks, defensive systems for protection of urban areas and high-value facilities from biological and chemical threats have been deployed. This paper reviews analyses of such scenarios and of the efficacy of potential response options, discusses defensive systems that have been deployed and detectors that are being developed, and finally outlines the detection systems that will be needed for improved CB defense in the future. Sandia's collaboration with San Francisco International Airport on CB defense will also be briefly reviewed, including an overview of airport facility defense guidelines produced in collaboration with Lawrence Berkeley National Laboratory. The analyses that will be discussed were conducted by Sandia National Laboratories' Systems Studies Department in support of the U.S. Department of Homeland Security (DHS) Science and Technology Directorate, and include quantitative analyses utilizing simulation models developed through close collaboration with subject matter experts, such as public health officials in urban areas and biological defense experts.

Biodetection instrumentation that is capable of functioning effectively outside the controlled laboratory environment is critical for the detection of health threats, and is a crucial technology for Health Security. Experience in bringing technologies from the basic research laboratory to integrated fieldable instruments suggests lessons for the engineering of these systems. This overview will cover several classes of such devices, with examples from systems developed for homeland security missions by Lawrence Livermore National Laboratory (LLNL). Recent trends suggest that front-end sample processing is becoming a critical performance-determining factor for many classes of fieldable biodetection devices. This paper introduces some results of a recent study that was undertaken to assess the requirements and potential technologies for next-generation integrated sample processing.

A wide variety of technical needs exist for surveillance, monitoring, identifying, or detecting pathogens with potential use as biological terrorism or warfare agents. Because the needs vary greatly among diverse applications, tailored systems are needed that meet performance, information, and cost requirements. A systems perspective allows developers to identify chokepoints for each application, and focus R&D investments on the limiting factors. Surveillance and detection systems are comprised of three primary components: information (markers), chemistries (assays), and instrumentation for "readout". Careful consideration of these components within the context of each application will allow for increases in efficiency and performance not generally realized when researchers focus on a single component in isolation. In fact, many application requirements can be met with simple novel combinations of existing technologies, without the need for huge investments in basic research. Here we discuss some of the key parameters for surveillance, detection, and identification of biothreat agents, and provide examples of focused development that addresses key bottlenecks, and greatly improve system performance.

CdZnTe (CZT) is a very promising material for nuclear-radiation detectors. CZT detectors operate at ambient temperatures and offer high detection efficiency and excellent energy resolution, placing them ahead of high-purity Ge for those applications where cryogenic cooling is problematic. The progress achieved in CZT detectors over the past decade is founded on the developments of robust detector designs and readout electronics, both of which helped to overcome the effects of carrier trapping. Because the holes have low mobility, only electrons can be used to generate signals in thick CZT detectors, so one must account for the variation of the output signal versus the locations of the interaction points. To obtain high spectral resolution, the detector's design should provide a means to eliminate this dependence throughout the entire volume of the device. In reality, the sensitive volume of any ionization detector invariably has two regions. In the first, adjacent to the collecting electrode, the amplitude of the output signal rapidly increases almost to its maximum as the interaction point is located farther from the anode; in the rest of the volume, the output signal remains nearly constant. Thus, the quality of CZT detector designs can be characterized based on the magnitude of the signals variations in the drift region and the ratio between the volumes of the drift and induction regions. The former determines the "geometrical" width of the photopeak, i.e., the line width that affects the total energy resolution and is attributed to the device's geometry when all other factors are neglected. The latter determines the photopeak efficiency and the area under the continuum in the pulse-height spectra. In this work, we describe our findings from systematizing different designs of CZT detectors and evaluating their performance based on these two criteria.

Pulsed neutron interrogation methods for detection of Special Nuclear Materials are being developed. Fast prompt neutrons from thermal neutron-induced fissions are detected in the time intervals following 100-μs neutron bursts from a pulsed D-T neutron generator operating at 1000 pulses per second. Silicon Carbide semiconductor neutron detectors are used to detect fission neutrons in the 30-840 μs time intervals following each 14-MeV D-T neutron pulse. Optimization of the neutron detectors has led to dramatic reduction of detector background and improvement of the signal-to-noise ratio for Special Nuclear Material detection. Detection of Special Nuclear Materials in the presence of lead, cadmium and plywood shielding has been demonstrated. Generally, the introduction of shielding leads to short thermal neutron die-away times of 100-200 μs or less. The pulsed neutron interrogation method developed allows detection of the neutron signal even when the die-away time is less than 100 μs.

Current requirements of some Homeland Security active interrogation projects for the detection of Special Nuclear Material (SNM) necessitate the development of faster inspection and acquisition capabilities. In order to do so, fast detectors which can operate during and shortly after intense interrogation radiation flashes are being developed. Novel silicon carbide (SiC) semiconductor Schottky diodes have been utilized as robust neutron and photon detectors in both pulsed photon and pulsed neutron fields and are being integrated into active inspection environments to allow exploitation of both prompt and delayed emissions. These detectors have demonstrated the capability of detecting both photon and neutron events during intense photon flashes typical of an active inspection environment. Beyond the inherent insensitivity of SiC to gamma radiation, fast digitization and processing has demonstrated that pulse shape discrimination (PSD) in combination with amplitude discrimination can further suppress unwanted gamma signals and extract fast neutron signatures. Usable neutron signals have been extracted from mixed radiation fields where the background has exceeded the signals of interest by >1000:1.

Simulations and experiments have been carried out to explore using a plastic scintillator as a dosimetry probe in the vicinity of a pulsed bremsstrahlung source in the range 4 to 20 MeV. Taking advantage of the tissue-equivalent properties of this detector in conjunction with the use of a fast digital signal processor near real-time dosimetry was shown to be possible. The importance of accounting for a broad energy electron beam in bremsstrahlung production, and photon scattering and build-up, in correctly interpreting dosimetry results at long stand-off distances is highlighted by comparing real world experiments with ideal geometry simulations. Close agreement was found between absorbed energy calculations based upon spectroscopic techniques and calculations based upon signal integration, showing a ratio between 10 MeV absorbed dose to 12 MeV absorbed dose of 0.58 at a distance of 91.4 m from the accelerator. This is compared with an idealized model simulation with a monoenergetic electron beam and without scattering, where the ratio was 0.46.

Extensive work has been published on millimetre wave active and passive detection and imaging of metallic objects concealed under clothing. We propose and demonstrate a technique for revealing the depth as well as the outline of partially transparent objects, which is especially suited to imaging layer materials such as explosives and drugs. The technique uses a focussed and scanned FMCW source, swept through many GHz to reveal this structure. The principle involved is that a parallel sided dielectric slab produces reflections at both its upper and lower surfaces, acting as a Fabry-Perot interferometer. This produces a pattern of alternating reflected peaks and troughs in frequency space. Fourier or Burg transforming this pattern into z-space generates a peak at the thickness of the irradiated sample. It could be argued that though such a technique may work for single uniform slabs of dielectric material, it will give results of little or no significance when the sample both scatters the incident radiation and gives erratic reflectivities due to its non-uniform thickness and permittivity . We show results for a variety of materials such as explosive simulants, powder and drugs, both alone and concealed under clothing or in a rucksack, which display strongly directional reflectivities at millimeter wavelengths, and whose location is well displayed by a varying thickness parameter as the millimetre beam is scanned across the target. With this system we find that samples can easily be detected at standoff distances of at least 4.6m.

Non-invasive real-time detection and identification of high explosives and improvised explosive devices, illicit materials hidden inside suitcases, vehicles, containers or behind metal and non-metal walls become critically important for safety and security worldwide. In this paper we will discuss non-scanning, portable real-time detection X-ray backscattering system based on novel Lobster-Eye X-ray focusing optics, which focuses backscatter photons from fully obscured objects several meters away that are being irradiated by short high-power X-ray pulses. Due to the ability of Lobster-Eye lenses to focus X-rays, such imaging systems collect more photons into a smaller spot, compared to traditional pinhole systems. This results in a higher signal-to-noise ratio and better spatial resolution. The signal-to-noise ratio can be further improved by using pulsed X-ray irradiation and a gated X-ray camera. The images can be further improved by software processing, which allows to reconstruct the object with high accuracy adequate for detection with high probability and low false alarm rate.

Widespread contamination of underground environments with dense non-aqueous phase liquids (DNAPLs) is of great concern to the public, military, and industrial sectors. Proper management of contaminated sites requires detection and monitoring of the contaminants, and accurate knowledge of their transport behavior in underground environments. Over the last years we have done great efforts to develop and integrate technologies that serve to locate contamination and monitor transport mechanism underground. In this paper, we describe a two-dimensional multiphase flow experiment to develop and evaluate two modes of concurrent detection and monitoring technologies: Cross Well Radar (CWR) and Image Analysis (IA). Loop antennas preset at specific locations in the tank are used to evaluate wave scattering properties of the soil under different conditions, while color images are acquired. The electromagnetic response in the CWR antennas and IA are used to establish the relation between electrical soil properties variations and changes spatial and temporal mass of water and contaminants. The technologies used in this research are both in development, but they can be successful tools for the detection, monitoring and imagining of underground contaminants and process. Once develop, the technology may be applied for detecting and monitoring other buried objects.

We report here on the development of neutron and photon sources for use in imaging and active interrogation applications, where there is a growing urgency for more advanced interrogation tools. These devices include high yield D-D, D-T and T-T fusion reaction based neutron generators and also low energy nuclear reaction based high-energy gamma generators. One common feature in these various devices is the use of a high-efficiency, RF-induction discharge ion source. This discharge method provides high plasma density for high output current, high atomic species from molecular gases for high efficiency neutron or gamma generation and long lifetime. Predictable discharge characteristics of these plasma generators allow accurate modeling for both the beam dynamics and for the heat loads at the target spot. Current status of the neutron and gamma generator development with experimental data will be presented.

Terrorists both with IEDs and suicide bombers are targeting civilian infrastructures such as transportation systems. Although explosive detection technologies exist and are used effectively in aviation, these technologies do not lend themselves well to protecting open architecture soft targets, as they are focused on a checkpoint form factor that limits throughput. However, remote detection of explosives and other chemicals would enable these kinds of targets to be protected without interrupting the flow of commerce. Tunable mid-IR laser technology offers the opportunity to detect explosives and other chemicals remotely and quickly. Most chemical compounds, including explosives, have their fundamental vibrational modes in the mid-infrared region (3 to 15μm). There are a variety of techniques that focus on examining interactions that have proven effective in the laboratory but could never work in the field due to complexity, size, reliability and cost. Daylight Solutions has solved these problems by integrating quantum cascade gain media into external tunable cavities. This has resulted in miniaturized, broadly tunable mid-IR laser sources. The laser sources have a capability to tune to +/- 5% of their center wavelength, which means they can sweep through an entire absorption spectrum to ensure very good detection and false alarm performance compared with fixed wavelength devices. These devices are also highly portable, operate at room temperature, and generate 10's to 100's of mW in optical power, in pulsed and continuous wave configurations. Daylight Solutions is in the process of developing a variety of standoff explosive and chemical weapon detection systems using this technology.

Large area x-ray detectors based on phosphors coupled to flat panel amorphous silicon diode technology offer significant advances for cargo radiologic imaging. Flat panel area detectors provide large object coverage offering high throughput inspections to meet the high flow rate of container commerce. These detectors provide excellent spatial resolution when needed, and enhanced SNR through low noise electronics. If the resolution is reduced through pixel binning, further advances in SNR are achievable. Extended exposure imaging and frame averaging enables improved x-ray penetration of ultra-thick objects, or "select-your-own" contrast sensitivity at a rate many times faster than LDAs. The areal coverage of flat panel technology provides inherent volumetric imaging with the appropriate scanning methods. Flat panel area detectors have flexible designs in terms of electronic control, scintillator selection, pixel pitch, and frame rates. Their cost is becoming more competitive as production ramps up for the healthcare, nondestructive testing (NDT), and homeland protection industries. Typically used medical and industrial polycrystalline phosphor materials such as Gd2O2S:Tb (GOS) can be applied to megavolt applications if the phosphor layer is sufficiently thick to enhance x-ray absorption, and if a metal radiator is used to augment the quantum detection efficiency and reduce x-ray scatter. Phosphor layers ranging from 0.2-mm to 1-mm can be "sandwiched" between amorphous silicon flat panel diode arrays and metal radiators. Metal plates consisting of W, Pb or Cu, with thicknesses ranging from 0.25-mm to well over 1-mm can be used by covering the entire area of the phosphor plate. In some combinations of high density metal and phosphor layers, the metal plate provides an intensification of 25% in signal due to electron emission from the plate and subsequent excitation within the phosphor material. This further improves the SNR of the system.