Electronics & Software

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...

The HDF-EOS 2 and HDF-EOS 5 Compatibility Library contains C-language functions that provide uniform access to HDF-EOS 2 and HDF-EOS 5 files through one set of application programming interface (API) calls. (“HDF-EOS 2” and “HDF-EOS 5” are defined in the immediately preceding article.) Without...

A shell script has been written as a means of automatically making HDF-EOS-formatted data sets available via the World Wide Web. (“HDF-EOS” and variants thereof are defined in the first of the two immediately preceding articles.) The shell script chains together some software tools developed by the Data Usability Group at...

A computer program partly automates the task of determining whether an HDF-EOS 5 file is valid in that it conforms to specifications for such characteristics as attribute names, dimensionality of data products, and ranges of legal data values. [“HDF-EOS” and variants thereof are defined in “Converting EOS Data From HDF-EOS...

An Extensible Markup Language (XML) document type definition (DTD) standard for the structure and contents of HDF-EOS files and their contents, and an equivalent standard in the form of schemas, have been developed. (“HDF-EOS” and variants thereof are defined in the first two of four related articles immediately...

A computer program recreates an HDF-EOS file from an Extensible Markup Language (XML) representation of the contents of that file. (“HDF-EOS” and variants thereof are defined in the first of five related articles that immediately precede this article.) This program is one of two programs written to enable testing...

A computer program called “42” simulates the attitudes and trajectories of multiple spacecraft flying in formation anywhere in the Solar System. The rotational dynamics are represented by high-fidelity models of spacecraft, each comprising as many as three connected rigid bodies and...

This Mathematica script defines a color function to be used with Mathematica’s plotting modules for differentiating data attaining both positive and negative values. Positive values are shown as shades of blue, and negative values are shown in red. The intensity of the color reflects the...

Global Alert Resolution Network (GARNET) is a software system for delivering emergency alerts as well as less-urgent messages to members of the Goddard Space Flight Center work force via an intranet or the Internet, and can be adapted to similar use in other large organizations. Messages can be...

A one-page document describes a Ka-band transponder being developed for use in deep-space radio science. The transponder receives in the Deep Space Network (DSN) uplink frequency band of 34.2 to 34.7 GHz, transmits in the 31.8 to 32.3 GHz DSN downlink band, and performs regenerative ranging on a DSN...

A document discusses the replication of the functionality of the onboard space-shuttle general-purpose computers (GPCs) in field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The purpose of the replication effort is to enable utilization of proven...

A document discusses work that obtains a low-dimensional model that captures both temporal and spatial flow by constructing spatial and temporal four-mode models for two classic flow problems. The models are based on the proper orthogonal decomposition at two reference Reynolds numbers....

Register today for NASA Tech Briefs' National Nano Engineering Conference (NNEC), the premier event focused on current and future developments in engineering innovations at the nanoscale. The event returns to Boston this year on November 12-13 at the Boston Colonnade Hotel, featuring the fourth annual Nano 50...

A prototype of an advanced robotic vision system both (1) measures its own motion with respect to a stationary background and (2) detects other moving objects and estimates their motions, all by use of visual cues. Like some prior robotic and other optoelectronic vision systems, this...