Simulating laser distractions with a high dynamic range display

The US Air Force Research Laboratory has actively pursued the development of the Chemical Oxygen-Iodine Laser (COIL) since its invention in 19771. The power scaling potential of the COIL was verified in the late 1980's on the RotoCOlL device, which was later decommissioned. A smaller COIL teststand (ReCOIL) was then upgraded with a rotating-disk oxygen generator and a variable-height slit nozzle to become the principal testbed for continued COIL development. The modified device was named the Research assessment evice Iodine chemical Laser (RADICL). RADICL has supported several major test campaigns during the past 9 years, many of which have been published. These include 2-D gain maps2, iodine dissociation studies3, magnetic gainswitching demonstrations4, mode-locking5, metal cutting/fiber delivery demonstrations, and more recently measurements of water concentration and oxygen yield . Areview of the major results of these test programs and previously unpublished data are presented.

This symposium describes collaborative research on neuroergonomics, technology, and cognition being conducted at George Mason University and the US Air Force Research Laboratory (AFRL) as part of the Center of Excellence in Neuroergonomics, Technology, and Cognition (CENTEC). Six presentations describe the latest developments in neuroergonomics research conducted by CENTEC scientists. The individual papers cover studies of: (1) adaptive learning systems; (2) neurobehavioral synchronicity during team performance; (3) genetics and individual differences in decision making; (4) vigilance and mindlessness; (5) interruptions and multi-tasking; and (6) development of a simulation capability that integrates measures across these domains and levels of analysis.

: The recent investigations of deoxyribonucleic acid (DNA) for use in non-linear optics (NLO) are an important breakthrough. Excellent optical quality thin films of DNA were obtained by Ogata in Japan and researchers at AFRL. Recent studies suggest that DNA may prove to be a more suitable material than the polymer currently used for optical waveguide devices, due to its optical and electromagnetic properties, resistance to solvents used in device fabrication, and it is biodegradable and inexpensive. The objective was to introduce active molecules within thin films of DNA in view of obtaining highly luminescent systems by three-photon absorption (3PA) and four-photon absorption (4PA), comparing results with analog poly(methyl methacrylate) (PMMA)-based host materials, in order to advance the understanding of DNA for non-linear optics. Eight chromophores of different structures (push-pull, quadrupole, bi-chromophore) were synthetised. Most these chromophores present an absorption band around 500 nm, allowing to expect 3PA properties. Spectroscopic properties are preserved in DNA-CTMA and PMMA thin films with fluorescence properties in the NIR. Unlike in PMMA, chromophores fluorescence efficiency in DNACTMA seems to depend strongly on the size of the molecule. The fluorescence efficiency decreases in DNA-CTMA for large molecules, leading to a higher efficiency in PMMA, while shortest molecules with a similar charge transfer present higher response in DNA. The confirmation of these results by 3PA should be performed in the group of Dr. James Grote (US Air Force Research Laboratory). These results are promising for the design of DNA-based highly fluorescent displays by multiphotonic excitation.

Protonex to extend soldier-worn portable power management

This paper presents recent progress of the research performed as part of the NRC’s participation in the NATO AVT-149 Unsteady Low-Re Aerodynamics Task Group. Results obtained using the NRC-IAR in-house code INSflow on an SD7003 airfoil compared with experimental results from the US Air Force Research Laboratory (AFRL) indicate that fully three-dimensional (3D) flow separation and stall occur during the flapping motions.

ABSTRACTLaser guide stars have increased the utility of adaptive optics systems by expanding the number of observable objects. The most common type of laser excites sodium in the mesosphere, and mesospheric sodium density is key to the performance of the laser. While a variety of observatories have conducted studies of the mesospheric sodium density, there are no published studies from Hawaii, which is home to some of the largest telescopes in the world. This paper presents mesospheric sodium densities measured by the University of Illinois lidar for 165 hr spanning 25 nights over 3 years. The mean sodium column density is 4.3 × 109 ± 0.2 × 109 cm−2, with a seasonal peak in the winter, as found at many other sites. The variations in a given night can be as high as the seasonal variation. We predict the average photon returns for the 15 W Keck II laser and a proposed 50 W laser at the Advanced Electro‐Optical System 3.6 m telescope for the observed sodium abundances.

ABSTRACTThe adaptive optics system of the 3.63 m AEOS telescope has a 941 actuator deformable mirror and is designed to work at visible wavelengths. It is one of the highest order operational adaptive optics systems. This paper details the design and performance of the system, including the Strehl ratio as a function of magnitude and the Strehl ratio as a function of the FWHM of the image. Sample images are also shown.

Missile Datcom (hereinafter referred to as Datcom) is an aerodynamic engineering calculation software developed by the US Air Force Research Laboratory. It is commonly used in the preliminary design of the shape scheme of missiles, aircraft and other aircraft. In this paper, Datcom is used to calculate the aerodynamic parameters of a two-dimensional ballistic correction projectile(D2BCP), and the calculated data is compared with the wind tunnel test data. The analysis results show that Datcom calculates the axial force coefficient (CA) of the projectile with large system deviation, however, the deviation can be eliminated by a certain compensation, thereby obtaining a more accurate CA of the projectile. Datcom calculates the normal force coefficient (CN) with high Mach number accuracy, but there is an unacceptable deviation of the projectile CN calculated at small angle of attack ( α ). The calculation of pitching moment coefficient with α (CMa) is higher, but the error is larger under individual Mach numbers.

This paper presents DAIDALUS (Detect and Avoid Alerting Logic for Unmanned Systems), a reference implementation of a detect and avoid concept intended to support the integration of Unmanned Aircraft Systems into civil airspace. DAIDALUS consists of self-separation and alerting algorithms that provide situational awareness to UAS remote pilots. These algorithms have been formally specified in a mathematical notation and verified for correctness in an interactive theorem prover. The software implementation has been verified against the formal models and validated against multiple stressing cases jointly developed by the US Air Force Research Laboratory, MIT Lincoln Laboratory, and NASA. The DAIDALUS reference implementation is currently under consideration for inclusion in the appendices to the Minimum Operational Performance Standards for Unmanned Aircraft Systems presently being developed by RTCA Special Committee 228.

HIFiRE (Hypersonic International Flight Research Experimentation) is a joint flight test program supported by the US Air Force Research Laboratory (AFRL) and the Australian Defence Science and Technology Organisation (DSTO). One of the main program goals is to gather basic research data on aspects of hypers onic flight not easily accessible to ground testing. Flight one focuses primarily on integration of instrumentation on the test vehicle, with application to boundary layer transition and shock interaction experiments. The HIFiRE 1 payload consists of a blunted 7° half angle cone and a cylinder/33° flare configuration. The payload will be boosted to Mach 8 utilizing a two stage Terrier-Orion sounding rocket. The payload was designed and manufactured to achieve the desired boundary layer transition and shock boundary layer interaction properties and collect the required data. Extensive analysis and ground testing was conducted to ensure the payload will survive the expected flight environment. The HIFiRE 1 launch campaign is scheduled for March 2010. A number of valuable lessons learned during the development of HIFiRE 1 are included in this paper. I. Introduction HIFiRE is a cooperative flight test program between the United States and Australia. The goal of this program is to advance technologies associated with hypersonic flight. Special emphas is is placed on exploring phenomena not readily accessible to ground tests. Fli ght one will focus on instrumentation an d telemetry systems to be used for flights occurring later in the program. The primary objec tive of HIFiRE 1 is to determine the feasibility of applying high-bandwidth instrumentation to aero-thermal flight measurements for short duration hypersonic flights at Mach numbers up to eight. The experiment will determine the suitability and survivability of multiple instrumentation types in this environment. The experiments will be incorporated into the nose cone of a Terrier-Orion launch vehicle 1 . This paper will refer to the nose cone as the “payload.” The measurement of three aero-thermal phenomena will serve to assess the performance of the instrumentation. The corresponding sub-experiments are, in order of priori ty, boundary layer transition (BLT), turbulent separated shock boundary layer interaction (SBLI), and optical measurement of mass capture (OMC). This paper describes the design, manufacture, integration and ground testing of the payload. It also includes valuable lessons that were learned during this process. The scientific motivations for the primary and secondary experiments on HIFiRE 1 have been discussed in a number of published papers 2,3,4,5,6,7,8,9 and will not be repeated here. Design parameters critical to the BLT experiment have been derived from past correlations, computational analyses and ground testing. The most critical paramete rs affecting the BLT experiment are surface roughness and step/gap sizes at and between payload sections. The most restrictive values were 0.08mm for an allowable discrete roughness and 0.001mm root mean square (rms) roughness at the nosetip (relaxing to 0.008mm rms aft of the nosetip). More recent results 3,10 indicated that larger values would have been acceptable, however the more restrictive roughness limits were employed for the payload design to provide a generous factor of safety for the experiment. A discrete roughness trip was installed on one side of the payload with the aim of extracting

The paper undertakes a comparison of two non-homogeneity detection (NHD) methods and addresses their impact on the performance of the adaptive matched filter (AMF) method and the normalized adaptive matched filter (NAME) method in severely non-homogeneous clutter scenarios. Performance analysis is carried out using simulated data as well as measured data from the US Air Force Research Laboratory's MCARM (multi-channel airborne radar measurement) program. Specific consideration is given to the computational cost of the NHD method and the sample support requirements. The paper presents a technique for speeding up the computations in the NHD. Performance is reported in terms of the probability of detection versus signal-to-noise ratio (SNR) for simulated data analyses.

Nonlinear Flight Control Systems Design for Hypersonic Vehicles: Results and Open Problems

Flexible hybrid electronics (FHE) integrate both traditional printed circuits, solder assembled standard and thinned silicon chips along with printable electronic materials and sensors. The combination results in high performance from thin, light weight, flexible devices that potentially could be manufactured at low cost. In this paper, flexible hybrid electronics technology is being used to develop a wearable ECG and skin temperature monitor. All components and materials were commercially available, and all fabrication processes were executed in manufacturing environments. The monitor is composed of a flexible polyimide substrate with printed ECG electrodes, a printed thermistor, and connecting traces printed on one surface, and the electronic components mounted on other. Both sides have copper metal circuits connected by copper plated through hole vias (THV). ECG signals are amplified, preconditioned and wirelessly transmitted via Bluetooth to a nearby handheld mobile phone or computer. The wearable monitor is 2x2 inches in size and has been demonstrated to produce high fidelity ECG signals at the host from both certified archived human ECG signals and ECG signals from human volunteers. The monitor reproduced the archived signals at the host from which a set of clinical parameters were calculated that closely matched those of the archived signals. Manufacturing challenges and device reliability will be discussed. Current work includes building upon this platform and integration of other monitoring and sensor devices included those that monitor for biomarkers in sweat. This work was sponsored by the NanoBio Manufacturing Consortium administered by the Flextech Alliance and funded by the US Air Force Research Laboratory.

Effects of diluent on laminar burning speed and flame structure of gas to liquid fuel air mixtures at high temperatures and moderate pressures

Recently there has been increasing interest in high quality ceramic laser gain materials, particularly for high-energy lasers, due to the successful application of high-volume advanced ceramics consolidation techniques to transparent oxide gain materials. In this paper, a brief comparison of manufacturing techniques is presented, including an overview of the co-precipitation process and the solid-state reaction process. Merits and risks of each will be presented from a processing viewpoint. Ceramic Nd:YAG in particular shows promise for high power laser design. The program reported here is also compiling a definitive database to compare ceramic and single crystal Nd:YAG materials. Uniform doping levels of up to 9 at% Nd3+ have been reported by Konoshima Chemical Co. in ceramic Nd:YAG, and studied by the US Army Research Laboratory and the US Air Force Research Laboratory. All ceramic Nd:YAG materials studied to date have exhibited similar, if not identical, spectroscopic parameters to those measured for single crystal samples. Thermal properties, laser damage thresholds and refractive indices for a range of temperatures and wavelengths are reported. Diode-pumped free running laser experiment results with highly concentrated (up to 8 at% Nd3+) ceramics and their comparison with our modeling results are presented. High pulse repetition frequency actively (AO) Q-switched laser experiments are in progress. While there are still challenges in the manufacturing of ceramic laser gain materials, and the benefits of the application of ceramic technology to laser material are yet to be fully realized, ceramic Nd:YAG shows promise and could provide new options to the laser design engineer.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.