Physical Sciences

Video Acuity Measurement System

The smallest letters that can be automatically identified are used to rate the video system.There is a widely acknowledged need for metrics to quantify the performance of video systems. Existing metrics are either difficult to measure or are largely theoretical. They do not reflect the full range of effects to which video may be subject, or do not relate easily to video performance in real-world tasks. The empirical Video Acuity metric is simple to measure and relates directly to task performance. Video acuity is determined by the smallest letters that can be automatically identified using a video system. It is expressed most conveniently in letters per degree of visual angle.

Posted in: Briefs, Physical Sciences, Test & Measurement, Mathematical analysis, Imaging and visualization

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Heat-Flow Probe Design and Development

Applications include measuring heat flow on Earth, where optimal thermal isolation of heaters/temperature sensors is important.The lunar regolith exhibits extremely low conductivity. Penetrating the regolith presents problems if the geo-technical properties of the regolith are not well understood and accounted for.

Posted in: Briefs, Physical Sciences, Test & Measurement, Test equipment and instrumentation, Thermal testing

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Solar Pumped Fiber Laser for Solar Sail Propulsion and Remote Power Transfer

The photovoltaic capability of any instrument can be enhanced by delivering extra power via a space-based, broadband laser beam.A new method has been developed to create coherent laser light efficiently with direct optical coupling of the Sun’s energy into the gain medium for multiple uses. New advances in solar cell photovoltaic (PV) technologies have greatly improved their efficiencies, mostly by improving their ability to convert many wavelengths or wider bands of the solar spectrum to electricity. New advances in actively doped fibers and optical glasses have been shown to produce very broad, multi-line absorption bands as well as stimulated emission lines, or laser lines. By designing the optical cavity system to feed back all emission bands into the gain media for amplification, a multi-wavelength source can be generated requiring no electronics.

Posted in: Briefs, Tech Briefs, Photonics, Physical Sciences, Electric power, Solar energy, Fibers

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Designing Smaller Magnets for the Large Hadron Collider

CERN designs a smaller and more powerful superconducting accelerator magnet using ANSYS multiphysics tools. The European Organization for Nuclear Research (CERN) requires new magnets that are smaller than their predecessors to accommodate new instrumentation. Because of their size, these magnets need to generate a 24 percent stronger magnetic field and the structure must provide for near-zero deformation of the conductor. Even a small deformation could increase the electrical resistance and raise the temperature enough to cause the conductor to lose its superconducting state. Engineers addressed this challenge using ANSYS electromagnetic, thermal, and structural simulation tools. Coupling the multiphysics domains in the ANSYS® Workbench® environment allowed the team to optimize the design by simultaneously considering all of the physics.

Posted in: Briefs, Physical Sciences, Software, Computer simulation, Computer software and hardware, Test equipment and instrumentation

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Electrical Calibration Source for Next-Generation Oscilloscope

Simulation helps cool the calibration head for the world’s fastest real-time oscilloscope. Keysight Technologies (formerly Agilent Technologies) develops world-leading equipment for solving tough measurement challenges. The company’s Infiniium 90000 Q-Series oscilloscope is the first to reach the 60 GHz barrier, enabling engineers to make measurements on a new generation of fiber optic transponders and systems that provide higher levels of data communication speeds than previously possible.

Posted in: Briefs, Physical Sciences, Software, Computational fluid dynamics, Computer software and hardware, Oscilloscopes, Test equipment and instrumentation

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Integrated Space Weather Analysis System (iSWA)

The iSWA system is a Web-based dissemination framework for NASA-relevant space weather information that combines forecasts based on the most advanced space weather models with concurrent space environment information. A key design driver for the iSWA system is to generate and present vast amounts of space weather resources in an intuitive, user-configurable, and adaptable format, enabling users to respond to current and future space weather impacts, as well as enabling post-impact analysis.

Posted in: Briefs, Physical Sciences, Software, Computer simulation, Mathematical analysis, Mathematical models, Computer software and hardware

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Automatic Localization of MSL Rover Mosaics in HiRISE Imagery

Applications include localization of autonomous vehicles in GPS-denied environments for military applications.Mars Science Laboratory (MSL) surface operations require precise and accurate knowledge of rover position. A key means of establishing/verifying position is to match ortho-rectified mosaics from the MSL onboard cameras to orbital data. Manual localization by matching mosaics to HiRISE imagery can be laborious and somewhat subjective. Ortho-rectified mosaics and orbital images differ dramatically in appearance, due to the extreme viewpoint change as well as occlusions (i.e. objects must be in line of sight) in the mosaics. A straightforward intensity-based matcher using correlation or local feature descriptors cannot cope with this difference. Instead, an information theoretic matcher was used that measures the mutual information between the mosaic and trial positions in the HiRISE imagery.

Posted in: Briefs, Physical Sciences, Software, Computer software and hardware, Imaging and visualization, Autonomous vehicles, Spacecraft

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