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

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

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

Electrical Characterization of Crystalline UO2, THO2 and U0.71TH0.29O2

Tracking and identifying radiation sources in the age of nuclear proliferation and well- resourced non-state actors is a national priority. Current neutron detection methods favor large detector volumes and long data collection times. Additionally, portable neutron detection methods have persistent problems with low signal-to-noise (small pulse height) and require large applied voltages.

Posted in: Briefs, Aerospace, Defense, Materials, Mechanical Components, MEMs, Semiconductors & ICs, Data Acquisition, Detectors, Sensors

Matrix-Free Assisted Laser Desorption Ionization Using Metal-Organic Frameworks

Matrix-assisted laser desorption/ionization (MALDI) is a soft ionization technique that is widely applied in the characterization of large biomolecules using various mass spectrometry (MS) analyzers, specifically, time-of-flight (TOF) analyzers. The MALDI process involves the deposition of an analyte solution onto a metal substrate before the addition of a matrix. The matrix/analyte dry spot is exposed to a UV laser, and the laser energy that is absorbed by the matrix/analyte is converted into heat energy that initiates charge transfer, which results in the desorption of the matrix and analyte molecules in ionized form. The positive ions are then accelerated through a vacuum into MS analyses.

Posted in: Briefs, Aerospace, Defense, Materials, Metals, Mechanical Components, MEMs, Data Acquisition, Sensors, Inspection Equipment, Instrumentation, Measuring Instruments, Monitoring, Test & Measurement

Geospatial Accuracy of Small Unmanned Airborne System Data in the Coastal Environment

The purpose of this study was to assess the ability of commonly available COTS software to produce geometrically accurate orthometric mosaics and terrain models from low-altitude UAS imagery.

Posted in: Briefs, Aeronautics, Aerospace, Aviation, Data Acquisition, Design, Imaging, Automation, Data Acquisition, Sensors, Software

Monitoring a Nearshore Beneficial Use Site: Application of a Benthic Sled and Video Annotation

The U.S. Army Corps of Engineers (USACE) Portland Districts (NWP) maintains safe and navigable waterways in Oregon through a variety of dredging projects, including channel deepening, and dredging sandbars. Placement of dredged sediment occurs at preselected, specific geographic areas categorized as nearshore beneficial use sites. Beneficial use sites are commonly monitored before, during, and after disposal, to evaluate dredge management practices and to avoid potentially adverse effects to the marine environment.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Environmental Monitoring, Cameras, Imaging, Video, Data Acquisition, Sensors, Instrumentation, Measuring Instruments, Monitoring, Test & Measurement

Sound Attenuation of Neoprene Wetsuit Hoods as a Function of Dive Depth and Acoustic Frequency: Hyperbaric Chamber Trials

The U.S. Navy is interested in strategies that divers could employ to protect them from loud underwater sounds. Sonar transmissions and other forms of underwater sound, such as that produced by noisy underwater tools, are an occupational hazard for U.S. Navy divers.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Machinery, Mechanical Components, Data Acquisition, Measuring Instruments, Test & Measurement

Localization and Mapping of Unknown Locations with Unmanned Ground Vehicles

The main goals of this research are to enhance a commercial off-the-shelf (COTS) software platform to support unmanned ground vehicles (UGVs) exploring the complex environment of tunnels, to test the platform within a simulation environment, and to validate the architecture through field- testing.

Posted in: Briefs, Aerospace, Defense, Batteries, Cameras, Lasers & Laser Systems, Photonics, Automation, Robotics, Data Acquisition, Sensors, Simulation Software, Software, Transportation

Deep Installation Method for Three-Component Seismic Sensors

Successful sensor installation is important, as it directly affects how the sensor will perform. If conducted incorrectly, it could seriously degrade the data received and collective system performance. This is especially pertinent for three-component (3C) seismic sensors that have the additional parameters of orientation and leveling in addition to the need to be well-coupled to the surrounding media.

Posted in: Briefs, Aerospace, Defense, Data Acquisition, Detectors, Sensors, Transducers