Special Coverage

Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management
Method of Bonding Dissimilar Materials
Sonar Inspection Robot System
Applying the Dynamic Inertia Measurement Method to Full-Scale Aerospace Vehicles
Method and Apparatus for Measuring Surface Air Pressure
Fully Premixed, Low-Emission, High-Pressure, Multi-Fuel Burner
Self-Healing Wire Insulation
Home

Enhanced Video-Oculography System

A previously developed video-oculography system has been enhanced for use in measuring vestibulo-ocular reflexes of a human subject in a centrifuge, motor vehicle, or other setting. The system as previously developed included a lightweight digital video camera mounted on goggles. The left eye was illuminated by an infrared light-emitting diode via a dichroic mirror, and the camera captured images of the left eye in infrared light. To extract eye-movement data, the digitized video images were processed by software running in a laptop computer. Eye movements were calibrated by having the subject view a target pattern, fixed with respect to the subject’s head, generated by a goggle-mounted laser with a diffraction grating.

Posted in: Briefs, Electronics & Computers

Read More >>

Joint Carrier-Phase Synchronization and LDPC Decoding

Soft feedback from an LDPC decoder would enhance performance of a PLL. A method has been proposed to increase the degree of synchronization of a radio receiver with the phase of a suppressed carrier signal modulated with a binary-phase-shift-keying (BPSK) or quaternary-phase-shift-keying (QPSK) signal representing a low- density parity-check (LDPC) code. This method is an extended version of the method described in “Using LDPC Code Constraints to Aid Recovery of Symbol Timing” (NPO-43112), NASA Tech Briefs, Vol. 32, No. 10 (October 2008), page 54. Both methods and the receiver architectures in which they would be implemented belong to a class of timing-recovery methods and corresponding receiver architectures characterized as pilotless in that they do not require transmission and reception of pilot signals.

Posted in: Briefs, Electronics & Computers

Read More >>

Dual-Polarization, Sideband-Separating, Balanced Receiver for 1.5 THz

Development is enabled by recent advances in simulation and microfabrication. A proposed heterodyne receiver would be capable of detecting electromagnetic radiation in both of two orthogonal linear polarizations, separating sidebands, and providing balanced outputs in a frequency band centered at 1.5 THz with a fractional bandwidth >40 percent. Dual-polarization, sideband-separating, and balanced-output receivers are well- known and have been used extensively at frequencies up to about 100 GHz; and there was an earlier proposal for such a receiver for frequencies up to 900 GHz. However, the present proposal represents the first realistic design concept for such a receiver capable of operating above 1 THz. The proposed receiver is intended to be a prototype of mass-producible receiver units, operating at frequencies up to 6 THz, that would be incorporated into highly sensitive heterodyne array instruments to be used in astronomical spectroscopic and imaging studies.

Posted in: Briefs, Electronics & Computers

Read More >>

Modular Battery Charge Controller

Distributed charge control and a masterless communication bus enhance this controller’s robustness for use in battery energy-storage applications. A new approach to masterless, distributed, digital-charge control for batteries requiring charge control has been developed and implemented. This approach is required in battery chemistries that need cell-level charge control for safety and is characterized by the use of one controller per cell, resulting in redundant sensors for critical components, such as voltage, temperature, and current. The charge controllers in a given battery interact in a masterless fashion for the purpose of cell balancing, charge control, and state-of-charge estimation. This makes the battery system invariably fault-tolerant.

Posted in: Briefs, Electronics & Computers

Read More >>

Re-Inventing the Number



Posted in: Blog

Read More >>

Reinventing the Tuktuk

In large cities across Asia, auto rickshaws (tuktuks) are one of the most important means of transportation. These tuktuks produce considerable CO2 emissions and air pollution, and their drivers are underpaid. Students participating in the Hybrid Auto Rickshaw project sought to cut CO2 emissions by 40%, while improving the economic positions of drivers.

Posted in: GDM, News, News, Energy, Energy Efficiency, Green Design & Manufacturing, Greenhouse Gases, Transportation

Read More >>

Green Aircraft Contest Takes Off

Today, the NASA Innovative Partnerships Program and the Comparative Aircraft Flight Efficiency (CAFE) Foundation officially announced the Green Flight Challenge. The flight efficiency competition is for aircraft that can average at least 100 mph on a 200-mile flight, while achieving greater than 200 passenger miles per gallon.

Posted in: GDM, News, News, Energy, Energy Efficiency, Energy Storage, Solar Power, Alternative Fuels, Green Design & Manufacturing, Transportation

Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.