Imaging

Imaging Detonations of Explosives

Using high-speed camera pyrometers to measure and map fireball/shock expansion velocities.

An effort has been made within the US Army Research Laboratory (ARL) to extract quantitative information on explosive performance from high-speed imaging of explosions. Explosive fireball surface temperatures are measured using imaging pyrometry (2-color 2-camera imaging pyrometer; full-color single-camera imaging pyrometer). Framing cameras are synchronized with pulsed laser illumination to measure fireball/shock expansion velocities, enabling calculation of peak air-shock pressures. Multicamera filtering at different wavelengths enables visualization of light emission by some reactant species participating in energy release during an explosion. Measurement of incident and reflected shock velocities is used to calculate shock energy on a target.

Posted in: Briefs, TSP, TSP, Aerospace, Imaging, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Thermodynamics, Thermodynamics, Defense industry, Missiles
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Terahertz (THz) Radar: A Solution For Degraded Visibility Environments (DVE)

Operating at higher frequencies than other types of radar produces tighter beams and finer resolution.

An accurate view of the physical world is frequently vital. For example, rotary wing aircraft pilots must have knowledge of the terrain in order to safely fly their aircraft. Therefore, systems capable of generating images of the environment of sufficient quality to facilitate the decision process are necessary. The product of such a system is illustrated in Figure 1.

Posted in: Briefs, TSP, TSP, Aerospace, Imaging, Cartography, Imaging, Imaging and visualization, Radar, Cartography, Imaging, Imaging and visualization, Radar, Terrain
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Multi-Channel Laser Absorption Spectrometer for Combustion Product Monitoring

This instrument can detect fires associated with electrical wiring and electronics packaging materials.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Tunable laser absorption spectrometer (TLAS) sensors enable gas monitoring with high accuracy and gas specificity, and can be optimized for continuous, maintenance-free operation on long-duration manned spacecraft missions. This innovation is a portable, five-channel TLAS instrument designed to continuously monitor ambient concentrations of carbon monoxide, hydrogen chloride, hydrogen cyanide, hydrogen fluoride, and carbon dioxide, with low-level detection limits below the standard spacecraft maximum allowable concentrations. Monitoring of these particular hazardous compounds allows tracking of ambient conditions and enables detection of fires associated with electrical wiring and electronics packaging materials.

Posted in: Briefs, TSP, Tech Briefs, Imaging, Photonics, Spectroscopy, Spectroscopy, Life support systems, Gases, Fire detection, Hazardous materials, Spacecraft
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Hollow-Core Fiber Lamp for Mercury Ion Clocks and Micro-Plasma Studies

These lamps may provide flexible spectroscopic solutions for chemical and medical analysis, as well as metrology and thin-film coating applications.

NASA’s Jet Propulsion Laboratory, Pasadena, California

The mercury linear ion trap frequency standard (LITS) at JPL has been demonstrated to have multiple potential applications in NASA deep space missions. An increase of the deep ultraviolet (DUV)/vacuum ultraviolet (VUV) light output from the plasma discharge lamp light source used in trapped ion clock atomic state preparation and detection would improve the clock signal-to-noise ratio (SNR) and decrease optical pumping times. Both lead to an improvement in clock short-term stability and/or enable the use of a local oscillator having lower cost and performance. A solution for higher intensity light generation is needed.

Posted in: Briefs, TSP, Tech Briefs, Imaging, Software, Exterior lighting, Fiber optics, Fiber optics, Test equipment and instrumentation, Spacecraft
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Thermal Cycle Qualification of Radiated Solar Arrays for 50 to 133 K Temperatures in Vacuum

A closed loop system needs no liquid helium.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Solar arrays (radiated or non-radiated) and other technologies are candidate materials for projects in JPL. Some of the projects need to qualify these potential technologies to cryogenic extreme temperatures (from 133 to 50 K or lower). Those technologies need to survive for more than 120 thermal cycles in a thermal vacuum environment to meet three times mission life of the ECM project per JPL design principles. There is not any published thermal cycling qualification data for solar arrays in vacuum to those of cryogenic temperatures. Therefore, an experimental assessment study was undertaken on behalf of the JPL pre-project office for the proposed Europa Clipper mission.

Posted in: Briefs, TSP, Imaging, Photonics, Solar energy, Thermal management, Thermal management, Thermal testing
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Web-Based Search Service to Support Imaging Spectrometer Instrument Operations

An adaptive matched-filter approach compensates for the context and background characteristics of each scene.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Imaging spectrometers yield rich and informative data products, but interpreting them demands time and expertise. There is a continual need for new algorithms and methods for rapid firstdraft analyses to assist analysts during instrument operations. Intelligent data analyses can summarize scenes to draft geologic maps, searching images to direct operator attention to key features. This validates data quality while facilitating rapid tactical decision-making to select follow-up targets. Ideally, these algorithms would operate in seconds, never grow bored, and be free from observation bias about the kinds of mineralogy that will be found.

Posted in: Briefs, TSP, Imaging, Photonics, Mathematical analysis, Internet, Spectroscopy, Internet, Spectroscopy, Data management
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Hermetic Phototube Housing

Goddard Space Flight Center, Greenbelt, Maryland

This innovation is a hermetically sealed case or very small chamber. A photomultiplier tube (PMT) is mounted inside the chamber. The circuit board is also installed inside the chamber with appropriate feedthroughs for signals. An adapter/floating mount called the phototube to light pipe system mount (PLPSM) allows the hermetic PMT housing to attach to the light guide.

Posted in: Briefs, TSP, Imaging, Photonics, Containers, Mountings
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Design, Fabrication, and Test of WFIRST/AFTA GRISM Assembly

Goddard Space Flight Center, Greenbelt, Maryland

This work originated with the Wide Field InfraRed Survey Telescope (WFIRST) slitless spectrometer design (GRISM assembly), which attempted to follow the Hubble Space Telescope (HST) method of employing a singleelement GRISM as a slitless spectroscope. However, WFIRST’s field of view (FOV) is ~100x of HST’s wide field camera, and the spectral resolution is ~5x higher with a relatively faster f/8 system. The design turned out to be extremely difficult using only one diffractive surface. Even with many freeform optical elements, and putting a grating on a toroid surface, the image performance was still not satisfactory.

Posted in: Briefs, TSP, Imaging, Photonics, Mirrors, Optics, Spectroscopy, Optics, Spectroscopy, Product development
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Spinal Ultrasound Just-in-Time Training Tool

This software facilitates ultrasound imaging of the cervical and lumbar spine by crewmembers in-flight.

Lyndon B. Johnson Space Center, Houston, Texas

Back pain and injury are recognized risks that can affect the well-being and performance of crewmembers during missions, as well as their long-term health. Spine elongation is a documented effect of microgravity, back pain is a common occurrence in early flight, and the post-flight incidence of spinal injury is higher than the population average. These observations suggest that spinal unloading results in a transition to a new set point for the spine, and causes discomfort and an increased risk of injury.

Posted in: Briefs, TSP, Imaging, Photonics, Personnel, Injury causation, Spacecraft
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Wide-Spectrum Organic Mass Spectrometer Using Far-Ultraviolet Ionization

Lyndon B. Johnson Space Center, Houston, Texas

Two-step laser desorption/photoionization mass spectrometry (L2MS) represents a powerful tool for the organic analysis of astromaterials. The technique has high sensitivity and requires little to no sample preparation.

Posted in: Briefs, TSP, Imaging, Photonics, Lasers, Spectroscopy, Lasers, Spectroscopy, Particulate matter (PM), Test equipment and instrumentation
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