Sensors

Luminescence Materials as Nanoparticle Thermal Sensors

The purpose of this research program was to create and study novel luminescence particles (phosphors} capable of sensing and retaining the time-temperature information to which they were exposed, therefore acting as nano- and microsized thermosensors. The thermometric property is the latent thermoluminescence (TL) signal associated with electron/hole pairs trapped at defect energy levels, which are differently affected by the environmental temperature.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Nanotechnology, Photonics, Sensors, Architecture, Sensors and actuators, Research and development, Nanomaterials, Thermal testing
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Using Dempster-Shafer Fusion for Personnel Intrusion Detection

The Dempster-Shafer (D-S) mass function is used in effect as a common representation of heterogeneous sensor data. In order to cast each data source in this form, first the raw data is reduced to points in a multi-dimensional feature space specific to each sensor. From there, an approach is outlined that uses a distance metric in the feature space to assign mass to each state in the class hierarchy. This hierarchy begins with the full frame of discernment which represents complete uncertainty. From there it proceeds as an n-array tree broken down into further subclasses until the finest granularity of classification for the specific sensor is reached.

Posted in: Briefs, Aerospace, Defense, Detectors, Sensors, Mathematical models, Sensors and actuators, Data management, Reliability
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Using Fisher Information Criteria for Chemical Sensor Selection via Convex Optimization Methods

The design of chemical sensor arrays from the standpoint of chemical sensor selection and error quantification has historically proceeded as an ad hoc process. Frequently, chemical sensors are developed not as general purpose sensing devices, but as analyte or chemical class specific detectors. When such single purpose devices are integrated together as a chemical sensor array, it is unclear a priori how well they will function in concert with each other to provide expanded capabilities, an observation that is true of the integration of analytical instruments as well.

Posted in: Briefs, Aerospace, Sensors, Optimization, Neural networks, Sensors and actuators, Identification, Chemicals
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Development of an Optically Modulated Scatterer Probe for a Near-Field Measurement System

Near-field radiation patterns are useful in diagnosing antenna array defects, measuring far-field antenna patterns where the far-field is prohibitively far, and locating field concentrations in high power microwave applications, which could lead to material breakdown. There are two categories of near-field measurements: direct and indirect. In a direct measurement, the field from the antenna-under-test (AUT) is directly measured by a probe whereas, in an indirect measurement, the field is inferred from the scattering off of a probe that is placed in the near-field.

Posted in: Briefs, Aerospace, Sensors, Finite element analysis, Measurements, Antennas, Radiation
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Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope

The primary metrics that prohibit the use of microelectromechanical systems (MEMS) gyroscopes for navigation-grade inertial navigation units (IMUs) are angle random walk (ARW), bias instability, and scale factor instability. The need for MEMS gyroscopes is due to their decreased cost, size, weight, and power (CSWaP) constraints compared to current navigation-grade solutions. Note that to avoid confusion, while in a statistical context a random walk describes a particular type of random process, ARW is used herein to quantify the effects of white, or Gaussian, noise processes on the rate estimate of a gyroscope.

Posted in: Briefs, Aerospace, Sensors, Mathematical analysis, Microelectricmechanical device, Navigation and guidance systems, Noise, Reliability
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Open Standard Middleware Enables New HPEC Solutions

The military embedded computing landscape has been transformed from where it was 20 years ago — and that has been almost entirely enabled by the ability of prime contractors, systems integrators, and OEMs to leverage the products of COTS manufacturers who take leading edge commercial technologies and apply them successfully to the world of military computing. A look at the commercial landscape today reveals cell phones that are putting vast amounts of location- aware information — and the ability to process that information — directly into the hands of consumers. The Internet of Things has become a deployable reality, with data derived from millions of connected sensors.

Posted in: Articles, Aerospace, Communications, Defense, Electronics & Computers, Sensors, Architecture, Computer software / hardware, Internet of things, Military vehicles and equipment
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Laser-Based Navigation Sensor Could be Standard for Planetary Landing Missions

A laser-guided navigation sensor that could help future rovers make safe, precise landings on Mars or destinations beyond was developed at NASA’s Langley Research Center. The Navigation Doppler Lidar (NDL) will act as a GPS for Mars spacecraft.

Posted in: INSIDER, News, Aerospace, Defense, Sensors
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InGaAs Imaging Sensor

New Imaging Technologies (Verrières le Buisson, France) introduces the NSC1401, a new analog wide dynamic range InGaAs sensor series in 320x256 pixels (QVGA). The NSC1401 uses a new generation of ROIC with 320x256 pixels at 25um pitch coupled to an InGaAs retina that operates in WDR mode and global shutter. The spectral response range goes from 900nm to 1700nm. The analog front end is designed to achieve extremely low input noise and ultra-fast response time down to 200ns for applications such as active imaging. The sensor operates both in linear integration mode and in log response. The NSC1401 can operate without TEC within an ambient temperature range from -40°C to 70°C.

Posted in: Products, News, Cameras, Imaging, Data Acquisition, Detectors, Sensors
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Detecting Radioactive Material from a Remote Distance

In 2004 British national Dhiren Barot was arrested for conspiring to commit a public nuisance by the use of radioactive materials, among other charges. Authorities claimed that Barot had researched the production of “dirty bombs,” and planned to detonate them in New York City, Washington DC, and other cities.

Posted in: News, Aerospace, Defense, Data Acquisition, Detectors
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Creating Simulated LIDAR Images of Human Poses in a Virtual Laboratory

LIDAR is a partial 3D standoff sensing method that illuminates a target with rotatory or flash laser beams, analyzes the reflected lights, and provides both the distance to the target’s surface and the target’s surface shape. An array of laser reflections can be used to map the facing-side surface of a target object as a partial point cloud. Unlike a 360° surface model generated by a traditional full body scanner, the partial point cloud from a LIDAR is a viewing angle dependent 3D representation of the target shape. The resolution of these maps depends on the density of the laser detector array; a good image of a human may require hundreds of detection pixels to capture enough detail to clearly detect changes in limb positions.

Posted in: Briefs, Sensors, Cartography, Lidar, Security systems, Anatomy, Kinematics, Medical equipment and supplies
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