Tech Briefs

A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

Briefs : Physical Sciences
Sub-Aperture Interferometers

Sub-aperture interferometers — also called wavefront-split interferometers — have been developed for simultaneously measuring displacements of multiple targets. The terms “sub-aperture” and “wavefront-split” signify that the original measurement light beam in an interferometer is split into multiple...

Briefs : Physical Sciences
Vacuum-Compatible Wideband White Light and Laser Combiner Source System

For the Space Interferometry Mission (SIM) Spectrum Calibration Development Unit (SCDU) testbed, wideband white light is used to simulate starlight. The white light source mount requires extremely stable pointing accuracy ( lights were coupled to a photonic crystal fiber...

Briefs : Physical Sciences
Stabilization of Phase of a Sinusoidal Signal Transmitted Over Optical Fiber

In the process of connecting widely distributed antennas into a coherent array, it is necessary to synchronize the timing of signals at the various locations. This can be accomplished by distributing a common reference signal from a central source, usually over optical...

Briefs : Physical Sciences
Optical Tapers as White-Light WGM Resonators

A theoretical analysis has revealed that tapered optical waveguides could be useful as white-light whispering-gallerymode (WGM) optical resonators. The compactness and the fixed-narrow-frequency- band nature of the resonances of prior microdisk and microsphere WGM resonators are advantageous in...

Briefs : Green Design & Manufacturing
Fine-Water-Mist Multiple-Orientation-Discharge Fire Extinguisher
A fine-water-mist fire-suppression device developed at John H. Glenn Research Center can be discharged uniformly in any orientation via a high-pressure gas propellant. Research in recent years has shown that fine water mist can be an effective alternative to ozone-destructive Halons.
Briefs : Energy
Fuel-Cell Water Separator
NASA Glenn Research Center has designed, built, and tested an innovative fuel-cell water separator that not only removes liquid water from a fuel cell’s exhaust ports, but does so with no moving parts or other power-consuming components. The separator employs the potential and kinetic energies already present in the...
Briefs : Electronics & Computers
Inexpensive Packaged Subharmonic Down-Converter MMICs

Two packaged monolithic microwave integrated-circuit (MMIC) mixers have been designed to operate as subharmonically pumped frequency down-converters in receivers of satellite- or ground-based digital communication systems. One operates a radio frequency (RF) between 17 and 20 GHz, the other...

Briefs : Materials
Extended Shelf Life for PMR Polyimide Resins and Prepregs

An improved class of formulations for PMR polyimide resins retards the imidization that undesirably occurs during handling and storage. While imidization is desired at the final (deliberate polymerization) stage of production of a polyimide, imidization results in premature aging when it...

Briefs : Materials
Silica-Filled EPDM Rubbers as Ablative Insulating Materials

Silica-filled polymers made from ethylene propylene diene monomer (EPDM) have been found to be useful as ablative thermal-insulation materials. These polymers have been investigated as candidates to replace some previously developed polymeric ablative rocket-engine insulating materials...

Briefs : Materials
Statistical Sampling of Tide Heights Study

The goal of the study was to determine if it was possible to reduce the cost of verifying computational models of tidal waves and currents. Statistical techniques were used to determine the least number of samples required, in a given situation, to remain statistically significant, and thereby reduce...

Briefs : Photonics/Optics
Multiparallel Three-Dimensional Optical Microscopy

Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and...

Briefs : Photonics/Optics
Sub-Aperture Interferometers

Sub-aperture interferometers — also called wavefront-split interferometers — have been developed for simultaneously measuring displacements of multiple targets. The terms “sub-aperture” and “wavefront-split” signify that the original measurement light beam in an interferometer is split into multiple...

Briefs : Photonics/Optics
Vacuum-Compatible Wideband White Light and Laser Combiner Source System

For the Space Interferometry Mission (SIM) Spectrum Calibration Development Unit (SCDU) testbed, wideband white light is used to simulate starlight. The white light source mount requires extremely stable pointing accuracy (hts were coupled to a photonic crystal fiber...

Briefs : Photonics/Optics
Stabilization of Phase of a Sinusoidal Signal Transmitted Over Optical Fiber

In the process of connecting widely distributed antennas into a coherent array, it is necessary to synchronize the timing of signals at the various locations. This can be accomplished by distributing a common reference signal from a central source, usually over optical...

Briefs : Photonics/Optics
Optical Tapers as White-Light WGM Resonators

A theoretical analysis has revealed that tapered optical waveguides could be useful as white-light whispering-gallery-mode (WGM) optical resonators. The compactness and the fixed-narrow-frequency-band nature of the resonances of prior microdisk and microsphere WGM resonators are advantageous in...

Briefs : Physical Sciences
Detecting Phase Boundaries in Hard-Sphere Suspensions

A special image-data-processing technique has been developed for use in experiments that involve observation, via optical microscopes equipped with electronic cameras, of moving boundaries between the colloidal-solid and colloidal-liquid phases of colloidal suspensions of monodisperse hard...

Briefs : Electronics & Computers
A Deep Space Network Portable Radio Science Receiver

The Radio Science Receiver (RSR) is an open-loop receiver installed in NASA’s Deep Space Network (DSN), which digitally filters and records intermediate-frequency (IF) analog signals. The RSR is an important tool for the Cassini Project, which uses it to measure perturbations of the...

Briefs : Physical Sciences
Using GPS to Detect Imminent Tsunamis

A promising method of detecting imminent tsunamis and estimating their destructive potential involves the use of Global Positioning System (GPS) data in addition to seismic data. Application of the method is expected to increase the reliability of global tsunami-warning systems, making it possible to save...

Briefs : Information Technology
Stream Flow Prediction by Remote Sensing and Genetic Programming

A genetic programming (GP)-based, nonlinear modeling structure relates soil moisture with synthetic-apertureradar (SAR) images to present representative soil moisture estimates at the watershed scale. Surface soil moisture measurement is difficult to obtain over a large area due to...

Briefs : Physical Sciences
Very-Long-Distance Remote Hearing and Vibrometry

A proposed development of laserbased instrumentation systems would extend the art of laser Doppler vibrometry beyond the prior limits of laserassisted remote hearing and industrial vibrometry for detecting defects in operating mechanisms. A system according to the proposal could covertly measure...

Briefs : Information Technology
Low-Complexity Lossless and Near-Lossless Data Compression Technique for Multispectral Imagery

This work extends the lossless data compression technique described in “Fast Lossless Compression of Multispectral-Image Data,” (NPO- 42517) NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26. The original technique was extended to include a...

Briefs : Semiconductors & ICs
Reconfigurable, Bi-Directional Flexfet Level Shifter for Low- Power, Rad-Hard Integration

Two prototype Reconfigurable, Bidirectional Flexfet Level Shifters (ReBiLS) have been developed, where one version is a stand-alone component designed to interface between external low voltage and high voltage, and the other version is an embedded...

Briefs : Semiconductors & ICs
Compact, Miniature MMIC Receiver Modules for an MMIC Array Spectrograph

A single-pixel prototype of a W-band detector module with a digital backend was developed to serve as a building block for large focal-plane arrays of monolithic millimeter-wave integrated circuit (MMIC) detectors. The module uses low-noise amplifiers, diode-based mixers,...

Briefs : Semiconductors & ICs
Magnetic-Field-Tunable Superconducting Rectifier

Superconducting electronic components have been developed that provide current rectification that is tunable by design and with an externally applied magnetic field to the circuit component. The superconducting material used in the device is relatively free of pinning sites with its critical...

Briefs : Semiconductors & ICs
Waveguide Transition for Submillimeter-Wave MMICs

An integrated waveguide-to-MMIC (monolithic microwave integrated circuit) chip operating in the 300-GHz range is designed to operate well on highpermittivity semiconductor substrates typical for an MMIC amplifier, and allows a wider MMIC substrate to be used, enabling integration with larger...

Briefs : Electronics & Computers
Pilotless Frame Synchronization Using LDPC Code Constraints

A method of pilotless frame synchronization has been devised for low-density parity-check (LDPC) codes. Heretofore, it has been conventional practice to add pilot symbols, which serve as frame-synchronization markers, to LDPC codes as well as to some other codes. The reception of a...

Briefs : Electronics & Computers
Modulation Based on Probability Density Functions

A proposed method of modulating a sinusoidal carrier signal to convey digital information involves the use of histograms representing probability density functions (PDFs) that characterize samples of the signal waveform. Although almost any modulation can be characterized as amplitude, phase, or...

Briefs : Electronics & Computers
Photonic Links for High-Performance Arraying of Antennas

An architecture for arraying microwave antennas in the next generation of NASA’s Deep Space Network (DSN) involves the use of all photonic links between (1) the antennas in a given array and (2) a signal processing center. As used here, “arraying” refers generally to any or all of...

Briefs : Electronics & Computers
Video System for Viewing From a Remote or Windowless Cockpit

A system of electronic hardware and software synthesizes, in nearly real time, an image of a portion of a scene surveyed by as many as eight video cameras aimed, in different directions, at portions of the scene. This is a prototype of systems that would enable a pilot to view the...

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