Communications

E-Textile Antenna Tuning Stitches

This technique can be used to tune a microstrip patch antenna.

Lyndon B. Johnson Space Center, Houston, Texas

A variety of antenna tuning techniques exist for conventionally constructed antenna structures, such that when an antenna is converted from a design to an actual fabricated structure, slight adjustments can be made to the fabricated structure to match the performance expected from the design. For microstrip antenna structures, for example, shorting pins may be added to adjust the resonant frequency of the structure, or the conducting top layer of the antenna may be intentionally constructed in a fashion such that portions of it may be removed in post-production tuning.

Posted in: Articles, Briefs, TSP, Communications, Antennas, Antennas, Antennas, Textiles
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Protograph-Based LDPC Bit-Interleaved Coded Modulation

Bandwidth and power-coded modulation schemes are very desirable for many applications in high-data-rate transmission over a given allocated bandwidth. The goal is to design such coded modulation system for a given throughput with the lowest possible signal-to-noise ratio for not only a channel with additive White Gaussian noise, but those channels that are impaired by fading, a typical channel in wireless communications and even satellite communications where mobiles may use Omni directional antennas.

Posted in: Articles, Briefs, TSP, Communications, Telecommunications, Telecommunications
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Flight Imagery Recorder Locator (FIRLo) and High-Temperature Radome

This technology is applicable to the commercial airline industry for locating “black boxes.”

NASA’s Jet Propulsion Laboratory, Pasadena, California

LDSD (Low Density Supersonic Decelerator) is a Mars EDL (entry, descent, and landing) Technology Development Project that launches three test vehicles out of the Pacific Missile Range Facility in Kauai. On the test vehicle, most mission science data can be recorded safely on land; however, high-speed and high-resolution imagery cannot be telemetered due to bandwidth constraints. Therefore, all information had to be recorded solely onboard the test vehicle; this unit is called the flight imagery recorder (FIR). A typical commercial airliner “black box” is only capable of recording on the order of gigabytes of data, whereas this work required on the order of terabytes (a few orders of magnitude larger).

Posted in: Articles, Briefs, Communications, Imaging, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Event data recorders, Spacecraft
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Multiparty Policy Negotiation Engine

Policy negotiation is the process of determining the “best” communication protocol that satisfies all requirements of all parties involved. The main challenge here is how to reconcile the various (and possibly conflicting) communications protocols used by different parties. The solution must use protocols available to all the parties involved, and should attempt to do so in the best way possible. Which protocols are commonly available, and what the definition of “best” is will be dependent on the parties involved and their individual communications priorities. Developing practical, sound, and automated ways to compose policies is a long-standing problem.

Posted in: Articles, Briefs, Communications, Communication protocols, Communication protocols
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Air Traffic Lab Answers Questions About Future Flying

The holiday season is upon us and that means crowded airports and delayed flights. Researchers at NASA's Langley Research Center are working to change that. They are conducting studies to help reshape the future of American air travel in a brand-new Air Traffic Operations Laboratory (ATOL). They are studying the Next Generation Air Transportation System, a new national airspace technology being implemented by the Federal Aviation Administration.

Posted in: News, Aerospace, Aviation, Communications, RF & Microwave Electronics
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Wireless Devices Used by Pilots are Vulnerable to Hacking

A new class of apps and wireless devices used by private pilots are vulnerable to a wide range of security attacks, which in some scenarios could lead to catastrophic outcomes, according to computer scientists at the University of California, San Diego and Johns Hopkins University. They examined three combinations of devices and apps most commonly used by private pilots to access the same information available to the pilot of a private jet at a fraction of the cost. All have to be paired with tablet computers to display information.

Posted in: News, Aerospace, Aviation, Communications, Defense, Electronics & Computers, PCs/Portable Computers
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NASA's Hot 100 Technologies: Communications

This technology uses recent advances in Radio Frequency Identification Devices, combined with smart software, to create an electronic firefighter evacuation trail and fire safety information location system. The trail can be followed out of a burning building even if interrupted by changing fire conditions.

Posted in: Articles, Techs for License, Communications
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Killer Robots - Army Studies Challenges of Remote Lethality

The military has used and experimented with robots that perform functions such as scouting and surveillance, carrying supplies and detecting and disposing of improvised homemade bombs. However, when it comes to integrating lethality, such as a weapon capable of firing 10 rounds per second onto an unmanned ground vehicle, issues arise such as safety, effectiveness and reliability, as well as military doctrine on how much human involvement is required.

Posted in: News, Communications, Defense, Automation, Robotics
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3D Audio Research Helps Make Cockpit Safer

Imagine yourself in a cockpit, flying a mission, listening to a multitude of critical voices delivering vital messages, all at the same time and from the same direction. Now imagine the same environment, except that the voices are now distinct and separate. The Air Force Research Laboratory (AFRL) has developed 3D sound technology that creates a sound environment that mimics the way the human body receives aural cues, much like 3D movies create the perception that the viewer is part of the movie.

Posted in: News, Aerospace, Aviation, Communications, RF & Microwave Electronics
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Ocean Gliders Measure Melting Polar Ice

The rapidly melting ice sheets on the coast of West Antarctica are a potentially major contributor to rising ocean levels worldwide. Although warm water near the coast is thought to be the main factor causing the ice to melt, the process by which this water ends up near the cold continent is not well understood.

Using robotic ocean gliders, Caltech researchers have now found that swirling ocean eddies, similar to atmospheric storms, play an important role in transporting these warm waters to the Antarctic coast—a discovery that will help the scientific community determine how rapidly the ice is melting and, as a result, how quickly ocean levels will rise.

"When you have a melting slab of ice, it can either melt from above because the atmosphere is getting warmer or it can melt from below because the ocean is warm," explains lead author Andrew Thompson, assistant professor of environmental science and engineering. "All of our evidence points to ocean warming as the most important factor affecting these ice shelves, so we wanted to understand the physics of how the heat gets there."

Because the gliders are small—only about six feet long—and are very energy efficient, they can sample the ocean for much longer periods than large ships can. When the glider surfaces every few hours, it "calls" the researchers via a mobile phone–like device located on the tail. The communication allows the researchers to almost immediately access the information the glider has collected.

Like airborne gliders, the bullet-shaped ocean gliders have no propeller; instead they use batteries to power a pump that changes the glider's buoyancy. When the pump pushes fluid into a compartment inside the glider, the glider becomes denser than seawater and less buoyant, thus causing it to sink. If the fluid is pumped instead into a bladder on the outside of the glider, the glider becomes less dense than seawater—and therefore more buoyant—ultimately rising to the surface. Like airborne gliders, wings convert this vertical lift into horizontal motion.

Source

Also: Learn about Remote Sensing of Ice Sheets and Snow.

Posted in: News, Communications, Batteries, Electronics & Computers, Environmental Monitoring, Green Design & Manufacturing, Motion Control, Automation, Robotics, Measuring Instruments, Monitoring, Test & Measurement
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