Sensors/Data Acquisition

Airborne Elastic Backscatter and Raman Polychromator for Ash Detection

Marshall Space Flight Center, Alabama Volcanic ash is a significant hazard to aircraft engine and electronics. It has caused damage to unwary aircraft and disrupted air travel for thousands of travelers, costing millions of dollars. The small, jagged fragments of rocks, minerals, and volcanic glass that constitute volcanic ash are about the size of sand and silt. Volcanic ash is hard, does not dissolve in water, is extremely abrasive and corrosive, and conducts electricity when wet. The upper winds transport the particles away to eventual dispersal in an ash cloud. Ash clouds typically form above 20,000 feet, but the lower limit of the initial cloud depends on both the height of the volcanic vent and the vigor with which material is ejected from it.

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Intelligent Displacement Sensor Deployment Using MTConnect Protocol over Ethernet

The protocol interfaces to an intelligent sensor and provides data gathering using a PC application. Stennis Space Center, Mississippi Quality measurements for design validation and certification requirements sometimes require hundreds or thousands of sensors and actuators. Maintaining such a complex system is difficult, especially over an extended time period and inevitable personnel changes. Many hours are spent tracking down sensor problems related to the sensor, associated cables, mounting hardware, or some part of the data acquisition system. These are expensive, labor-intensive hours that consume valuable technical resources.

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Active Remote-Sensing Radiometer

This technology can be used for security screening and security imaging, as well as automotive navigation in dust and fog conditions where machine vision performs poorly. NASA’s Jet Propulsion Laboratory, Pasadena, California Millimeter-wave (mm-wave) imaging techniques are already a popular solution for imaging through dust and fog. While mm-wave offers excellent penetration to dust when compared with infrared or optical sensing, the longer wavelengths create many problems associated with the specular response of surfaces at mm-wave. Generally, at mm-wave, the geometry and orientation of the target object has a larger influence on captured contrast than material properties by several orders of magnitude. While these effects can be somewhat mitigated with a radar imager, there is still a large contrast dependence on beam-target angle, and images are still entirely derived from geometry instead of material compositions.

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Pressure Sensor Using Piezoelectric Bending Resonators

This technology applies to any application in which high-pressure measurement is required. NASA’s Jet Propulsion Laboratory, Pasadena, California A pressure sensor was developed based on a piezoelectric bending resonator. The resonator is covered and mechanically coupled with a sealed enclosure. The impedance spectrum of the resonator changes with the deformation of the enclosure induced by pressure or force applied to the enclosure. The changes in the impedance can be mapped to exchanges in the external environment, and the shifts in the resonance can be used to track the pressure.

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Using a Ubiquitous Conductor to Power and Interrogate Wireless Passive Sensors and Construct a Sensor Network

Sensor nodes are used in health monitoring of aircraft and vehicles, building monitoring, human activity monitoring, and information collection for fire and disaster rescue. Langley Research Center, Hampton, Virginia Many methods have been developed for interrogation of wireless passive sensors. Surface acoustic wave (SAW) sensors and RF reflection sensors can receive and reflect electronic magnetic waves that are broadcast and received by the antennas. The interrogation distance can range from several meters to tens of meters. These previously developed technologies have limitations. The signal frequency is very high (usually at GHz level), which increases the difficulties in signal processing and interrogation system development, and the interrogation distance is limited by the power attenuation in the space. Longer interrogation distance requires higher-power-density electromagnetic (EM) waves in signal broadcasting, which increases the EMI hazard to environments.

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Full-Field Inverse Finite Element Method for Deformed Shape- and Stress-Sensing of Plate and Shell Structures

Real-time reconstruction of full-field structural displacements helps provide feedback to the actuation and control systems of aerospace vehicles with morphed-wing architecture. Langley Research Center, Hampton, Virginia Structural health management systems that, by way of real-time monitoring, help mitigate accidents due to structural failures, will become integral technologies of the next-generation aerospace vehicles. Advanced sensor arrays and signal processing technologies are utilized to provide optimally distributed in-situ sensor information related to the states of strain, temperature, and aerodynamic pressure. To process the massive quantities of measured data, and to infer physically admissible structural behavior, requires robust and computationally efficient physics-based algorithms.

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Pressure-Optimized Optical Breath Gas Analyzer for Portable Life Support Systems

This instrument could be used in trace gas sensor applications where rapid sampling in a compact package is required, such as in human-occupied closed volumes. Lyndon B. Johnson Space Center, Houston, Texas Optical detection of gaseous carbon dioxide, water vapor (humidity), and oxygen is desired in Portable Life Support Systems (PLSS) incorporating state-of-the-art CO2 scrubbing architectures. Earlier broadband detectors are nearing their end of life, and recent advances in laser diode technology make replacement of earlier technology compelling. The function of the infrared gas transducer used during extravehicular activity (EVA) in the current spacesuit is to measure and report the concentration of CO2 in the ventilation loop. The next-generation PLSS requires next-generation CO2 sensing technology with performance beyond that presently in use on the Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within spacesuits demands that optical sensors meet stringent size, weight, and power requirements. A sensor is required that is compact, low power, low mass, has rapid sampling capability, can operate over a wide pressure range, and can recover from condensing conditions.

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