Test & Measurement

Photogrammetric Recession Measurement

This method can be used to measure the recession of ablative materials in insulation coatings, ceramics and composites, arc-jet systems, and soil erosion. Ames Research Center, Moffett Field, California The testing of materials that ablate as a design function requires detailed time history of the ablation process. The rate at which the surface recedes during testing is a critically important measure of the performance of thermal protection system (TPS) materials like heat shields for aerospace vehicles. Photogrammetric recession measurement (PRM) meets these needs by recording the surface of the ablating model during heating in hyperthermal test facilities (arc-jets), using two high-resolution digital cameras capable of recording simultaneously. The cameras are calibrated to yield three-dimensional object space measurement for each stereo pair of images, producing surface recession data over the portion of the model for which both cameras share a view.

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Tissue-Equivalent Radiation Dosimeteron-a-Chip with Plastic Scintillation Material

This innovation uses solid-state technology to create a compact, lightweight, personal space radiation monitor. Lyndon B. Johnson Space Center, Houston, Texas The complexity of spaceflight design requires reliable, fault-tolerant equipment capable of providing real-time dosimetry during a mission, which is not feasible with existing thermoluminescent dosimeter (TLD) technology. Real-time monitoring is important for low-Earth-orbiting spacecraft and interplanetary spaceflight to alert the crew when solar particle events (SPE) increase the particle flux of the spacecraft environment. In this innovation, the personal dosimeter is comprised of a tissue-equivalent scintillator coupled to a solid-state photomultiplier.

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Measurement of Cryogenic Fluid Level with Laser Propagation and Surface Floor Reflection

The current float sensing system can be augmented with this new development. Stennis Space Center, Mississippi The risks associated with introducing new hardware and methods into an operational environment have in part prohibited cryogen level measurement technology from advancing. In prior art, measurements have been made with invasive probes immersed in the cryogenic fluid. Implementing this approach would require physical retrofitting, as well as requiring the measuring instrument to make contact with the harsh cryogen fluid environment. However, an externally mounted optical measurement system would mitigate these concerns. Therefore, an optical approach was developed that uses and augments existing validated technology in a manner that does not interfere with the current infrastructure.

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Video Acuity Measurement System

The smallest letters that can be automatically identified are used to rate the video system. Ames Research Center, Moffett Field, California 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.

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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. Marshall Space Flight Center, Alabama 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.

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Processing COSMIC/FORMOSAT-3 Data for Slant Total Electron Content Measurements

New leveling algorithm uses GPS multipath signals to provide an improved leveling of ionospheric measurements. NASA’s Jet Propulsion Laboratory, Pasadena, California The COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) mission has GPS (Global Positioning System) radio occultation dual-band receivers onboard. The received signals slice through the ionosphere, layer by layer, in much the same way as peeling off the layers of an onion. In order to use GPS signals for ionospheric measurements, they must be edited, phase leveled, and the hardware biases removed. The leveling algorithm used for ground-based GPS receivers is inadequate for space-based receivers due to substantially different multipath characteristics.

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Durability Analysis of a Vehicle by Virtual Test Model (VTM)

For accurate prediction of fatigue failure in structural components, accurate prediction of dynamic force histories is required. Ashok Leyland Ltd., Chennai, India The criterion for structural failure must be based on failure modes of the component being designed. If the component is to withstand millions of cycles of load application, criterion for fatigue failure must be used. Fatigue damage caused by repeated dynamic loads depends on the number of cycles and the frequency of significant stresses. Therefore, for accurate prediction of fatigue failure in structural components, accurate prediction of dynamic force histories is required.

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