Humans have been using rocket propulsion for almost a millennium, starting with Chinese rockets and “fire arrows” in the 13th century and continuing to the modern era's powerful Space Shuttle and Falcon rockets. For most of that history, rockets have been chemically fueled, but in the past century scientists and engineers have also experimented with electric rockets, also known as ion engines or ion propulsion systems.

There are those who think all cables are created equal. Well, they're not.

After a very successful trade show and conference in New Orleans last year, the Association for Unmanned Vehicle Systems International (AUVSI) is bringing this year's event, AUVSI XPONENTIAL 2017 to the Kay Bailey Hutchinson Convention Center in Dallas, TX. The event, which runs from May 8 – May 11, will feature more than 200 presentations and panel discussions focused on all aspects of the unmanned vehicle and robotics market. Over 650 exhibitors representing more than 20 different industries will be showcasing their latest technology to an estimated 7,000 attendees from all over the world.

Pulsed signals are widespread in radar and other electronic warfare (EW) applications, and they must be accurately measured for manufacturing, design of countermeasures, and threat assessment. Pulse measurements are an especially challenging area for signal analysis due to a combination of factors. Fortunately, many of the improving signal processing and analog-digital conversion technologies behind the generation of complex pulse environments also enable new techniques for effective pulse analysis.

When Malaysia Air Flight 370 disappeared somewhere over the Indian Ocean in 2014, it had flown far beyond radar range. Under a new space-based air tracking system — starting with a reconfigurable radio developed by NASA — no plane would ever be off the grid that way.

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.

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.

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.

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.

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.