Electronics & Software

An optically modulated field-effect transistor (OFET) based on a silicon carbide junction field-effect transistor (JFET) is under study as, potentially, a prototype of devices that could be useful for detecting ultraviolet light. The SiC OFET is an experimental device that is one of several devices,...

In this innovation, it is shown that a commonly used rule of thumb (that the truncation depth of a convolutional code should be five times the memory length, m, of the code) is accurate only for rate 1/2 codes. In fact, the truncation depth should be 2.5 m/(1 – r), where r is the code rate....

Suitably formulated spatial modulation of a scene imaged by a computed-tomography imaging spectrometer (CTIS) has been found to be useful as a means of improving the imaging performance of the CTIS. As used here, “spatial modulation” signifies the imposition of additional, artificial structure on...

A University of Michigan engineer has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power. Called VIVACE for Vortex Induced Vibrations for Aquatic Clean Energy, the hydrokinetic energy system relies on vortex-induced vibrations, undulations that a...

LiCoO2 and LiNiO2 fibers have been investigated as alternatives to LiCoO2 and LiNiO2 powders used as lithium-intercalation compounds in cathodes of rechargeable lithium-ion electrochemical cells. In making such a cathode, LiCoO2 or LiNiO2 powder is mixed with a binder [e.g.,...

The term “electromagnetically clean solar array” (EMCSA) refers to a panel that contains a planar array of solar photovoltaic cells. The cells are laminated with shielding, narrow-current-loop wiring, and structural supports. EMCSAs could be useful in applications that require limited electromagnetic interference.

ADROIT is a developmental computer program for real-time distribution of complex data streams for display on Web-enabled, portable terminals held by members of an operational team of a spacecraft-command- and-control center who may be located away from the center. Examples of such...

A number of science data sets are derived from the observations of the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard NASA’s Terra and Aqua satellites. These data typically contain information on retrieval techniques, quality-control flags, and geo-referencing information. These datasets,...

An algorithm has been devised to reduce ground clutter in the data products of the CloudSat Cloud Profiling Radar (CPR), which is a nadir-looking radar instrument, in orbit around the Earth, that measures power backscattered by clouds as a function of distance from the instrument. Ground...

Progress has been made in a continuing effort to develop a spaceborne computer system for processing readout data from a Fourier-transform infrared (FTIR) spectrometer to reduce the volume of data transmitted to Earth. The approach followed in this effort, oriented toward reducing design time...

An effort related to that described in the preceding article focuses on developing a spaceborne processing platform for fast and accurate onboard classification of image data, a critical part of modern satellite image processing. The approach again has been to exploit the versatility of...

A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation...

Progress has been made in a continuing effort to develop multi-chip power modules (SiC MCPMs). This effort at an earlier stage was reported in “SiC Multi-Chip Power Modules as Power-System Building Blocks” (LEW-18008-1), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 28.

A radio communication and ranging system has been proposed for determining the relative position and orientations of two approaching spacecraft to provide guidance for docking maneuvers. On Earth, the system could be used similarly for guiding approaching aircraft and for automated...

A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply...

A theoretical and experimental study was conducted of the limit imposed by photon-detector jitter on the capacity of a pulse-position- modulated optical communication system in which the receiver operates in a photon-counting (weak-signal) regime. Photon-detector jitter is a random delay between...

The term “electromagnetically clean solar array” (“EMCSA”) refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interference to and...

Subsystem Multiplexer (Sub-MUX) Quintron Systems Santa Maria, CA 805-928-4343 www.quintron.com NASA has awarded Quintron Systems an Indefinite-Delivery- Indefinite-Quantity (IDIQ) contract, and the first task order is for a command and control communications system that...

A C-language computer program accepts, as input, a set of scientific data and metadata from an Earth Observing System (EOS) satellite and converts the set from (1) the format in which it was created and delivered to (2) another format for processing and exchange of data on Earth. The first-mentioned format...