Tech Briefs

Influence of Leading-Edge Oscillatory Blowing on Time-Accurate Dynamic Store Separation

Increasing the operational efficiency of weapons employed in hostile environments is a high priority of the United States Air Force (USAF). In recent history, the USAF has made a move to smaller and internally stored weapons, especially for fighter aircraft. Maintaining a low radar cross section signature, and thus a low observable air vehicle, is desirable so the aircraft is less detectable by the enemy.

Posted in: Briefs, Aeronautics, Aerospace, Aviation, Data Acquisition, Defense, Motors & Drives, Data Acquisition, Test & Measurement
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Green’s Function Extraction from Atmospheric Acoustic Propagation

Acoustic waves propagating in the atmosphere may undergo many effects including refraction by temperature and wind velocity gradients, scattering by atmospheric turbulence, absorption by the atmosphere (fluid), diffraction by terrain features, and absorption and reflection by a porous ground. As a result, there may be insonification in acoustic shadow zones, amplitude and phase fluctuations of the propagating sound signals, loss of signal coherence, changes in the interference maxima and minima of the direct ground reflected waves, and multipath effects. Understanding these effects is important for a variety of military applications, such as acoustic source localization and classification, noise propagation in the atmosphere, and the development of new remote sensing techniques of the atmosphere.

Posted in: Briefs, Aerospace, Defense, RF & Microwave Electronics, Detectors, Sensors
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Spatiotemporal Imaging Exploiting Structured Sparsity

Spatiotemporal imaging contains a large class of imaging problems, which involve collecting a sequence of data sets to resolve both the spatial and temporal (or spectral) distributions of some physics quantity. This capability is exploited in numerous different fields such as remote sensing, security surveillance systems, astronomical imaging, and biomedical imaging. One typical example is hyperspectral imaging, which is a powerful technology for remotely inferring the material properties of the objects in a scene of interest. Ultrasonic and thermal imaging are other important examples of spatiotemporal imaging where high spatial resolution is needed for urban planning, military planning, intelligence and disaster monitoring and evaluation.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Cameras, Imaging, Optics, Data Acquisition, Sensors
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Ultrafast Optics: Vector Cavity Lasers — Physics and Technology

Fiber lasers have found widespread applications in industrial material processing, scientific research and military systems due to their advantages of easy maintenance, excellent stability, compact size and low cost. One characteristic of fiber lasers, compared to other types of lasers, is that strong light is confined to propagating a long distance in a fiber core that has a very small cross-sectional area. This has the consequence that the nonlinear light interaction with the matter has a very long length. This results in the strength of all nonlinear optical processes being strongly amplified. This means that a conventionally weak, nonlinear optical effect can become significant. Therefore, apart from the practical applications, fiber lasers also constitute an ideal platform for the exploration of various complex nonlinear dynamics.

Posted in: Briefs, Aerospace, Defense, Fiber Optics, Lasers & Laser Systems, Optical Components, Optics, Photonics
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Integration of Adaptive Optics Into High-Energy Laser Modeling And Simulation

The U.S. Navy is constantly predicting future threats and contemplating new weapon technologies to counter them. One of those technologies is directed-energy (DE) weapons. Conventional weapons rely on the kinetic energy of projectiles. High-energy lasers (HELs), one type of directed-energy weapon, work in a fundamentally new way, using electromagnetic radiation to damage or destroy enemy assets.

Posted in: Briefs, Aerospace, Defense, Lasers & Laser Systems, Optics, Photonics, Simulation Software, Software
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3D Meta-Optics for High-Energy Lasers

The scope of this research radically changed the way novel components are designed and fabricated for high-energy applications. This 3D Meta-Optics platform was, and is, essentially engineering the electromagnetic fields in 3D dielectric structures. The results have provided a class of transformational optical components that can be integrated at all levels throughout a high-energy laser system.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Materials, Lasers & Laser Systems, Optical Components, Optics, Test & Measurement
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Feasibility Study of Portable Water Desalination Systems for Water Contingencies at Remote Navy Installations

The Department of the Navy (DON) has major installations located around the world. Twenty-two main installations operate outside the continental United States (OCONUS) and rely on on-base water processing facilities. These facilities serve a total population of 71,000 military and civilian personnel, and the water plants have a total production capacity of 15.7 million gallons per day.

Posted in: Briefs, Aerospace, Defense
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