Tech Briefs

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
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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
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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
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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
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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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Hands-on Cybersecurity Studies: Multi-Perspective Analysis of the WannaCry Ransomware

Ransomware is malware that obstructs a user from accessing digital assets through various mechanisms. These assets are held hostage and inaccessible until the user pays a ransom. In most cases, this is accomplished using encryption where, once the malicious program executes, it will target and encrypt certain files and will release the decryption key at the time of payment. Some ransomware instances target only certain common user-generated files such as media and documents. In this case, system files and others required for the operating system to function correctly (user authentication, process execution, etc.) are unaffected. Others encrypt much more and seek to lock out entire systems.

Posted in: Briefs, Aerospace, Defense, Software
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Thermal Conductivities of Some Polymers and Composites

Thermoset polymers are good electrical insulators that are used in applications ranging from electronics to composite armor. They are rather poor thermal conductors, however.

Posted in: Briefs, Aerospace, Defense, Electronic Components, Electronics, Electronics & Computers, Thermal Management, Composites, Materials, Instrumentation, Measuring Instruments, Test & Measurement
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