Special Coverage

Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines
Vibration Tables Shake Up Aerospace and Car Testing
Supercomputer Cooling System Uses Refrigerant to Replace Water
Computer Chips Calculate and Store in an Integrated Unit
Electron-to-Photon Communication for Quantum Computing

Parallel-Processing High-Rate Digital Demodulator ASIC

CMOS circuitry can be used instead of more expensive analog circuitry or GaAs-based kind.

An all-digital demodulator has been developed for receiving radio signals with multigigahertz carrier frequencies phase-modulated with digital data signals at bit rates of hundreds of millions of bits per second. The phase modulation could be either binary phase-shift keying (BPSK) or quadrature phase-shift keying (QPSK), including QPSK employing bandwidth efficient pulse-shaping methods. The demodulator has been implemented in complementary metal oxide semiconductor (CMOS) application-specific integrated circuit (ASIC) configured to utilize algorithms that process signal data in multiple parallel streams.

Posted in: Briefs, TSP, Electronics & Computers, Architecture, Communication protocols, Data exchange, Integrated circuits, Semiconductor devices

Reusable Software for Autonomous Diagnosis of Complex Systems

Software incorporates advances in several data analysis disciplines to enable autonomous self-monitoring.

A software system designed to provide a purely signal-based diagnosis of virtually any time-varying system has been developed. This software is part of an overall concept called “Beacon-based Exception Analysis for Multimissions,” or BEAM. This concept provides for real-time autonomous diagnostics and prognostics of virtually any complex system (e.g., intelligent spacecraft or advanced aircraft) by use of software executed on an embedded computer.

Posted in: Briefs, TSP, Electronics & Computers, Computer software and hardware, Diagnostics, Prognostics, Systems management

TAXI Direct-to-Disk Interface Demultiplexes Proprietarily Formatted Data

Data can be stored in channel files in a PC in real time.

The TAXI Direct-to-Disk interface is a special-purpose interface circuit for demultiplexing of data from a Racal Storeplex (or equivalent) multichannel recorder onto one or more hard disks that reside in, and/or are controlled by, a personal computer (PC). [The name “TAXI” as used here is derived from the acronym TAXI, which signifies transparent asynchronous transceiver interface.] The TAXI Direct-to-Disk interface was developed for original use in capturing data from instrumentation on a test stand in a NASA rocket-testing facility. The control, data-recording, and datapostprocessing equipment of the facility are located in a control room at a safe distance from the test stand. Heretofore, the transfer of data from the instrumentation to the postprocessing equipment has entailed post-test downloading via software, requiring many hours to days of post-test reduction before the data could be viewed in a channelized format. The installation of the TAXI Directto- Disk interface, in conjunction with other modifications, causes the transfer of data to take place in real time, so that the data are immediately available for review during or after the test.

Posted in: Briefs, Electronics & Computers, Architecture, Data exchange, Integrated circuits, Test equipment and instrumentation

Program Improves Transfer of Data From CAD to Machine Shops

The EMNet computer program has been developed to overcome the difficulties and reduce the errors that, heretofore, have been encountered in transferring data from computer-aided design (CAD) systems to computer numerically controlled (CNC) machines. EMNet could improve operations in almost any industrial machine shop that uses CNC equipment.

Posted in: Briefs, Software, CAD, CAM, and CAE, Data exchange, Computer integrated manufacturing, Manufacturing equipment and machinery

Compensating for Motion Errors in UWB SAR Data

Processing is implemented in two stages by a computationally efficient algorithm.

A method of processing data acquired by ultra-wide-band (UWB) syntheticaperture radar (SAR) provides for suppression of those errors that are caused by the undesired relative motion of the radar platform and the targets. This method involves, among other things, processing of data in the wave-number or frequency domain and the application of motion compensation as a function of the positions of a target relative to the radar platform.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Radar, Data management

Program for International-Temperature-Scale Calculations

A computer program implements several aspects of the International Temperature Scale of 1990 (ITS90).

Posted in: Briefs, TSP, Software, Measurements, Computer software and hardware, Thermodynamics, Standardization

Updated Global Atmospheric Reference Model Computer Programs

The 1999 version of the NASA/Marshall Space Flight Center Global Reference Atmospheric Model (GRAM-99) and version 3.8 of the Mars Global Reference Atmospheric Model (Mars- GRAM) are the latest in two series of computer programs for calculating selected physical properties of the atmospheres of Earth and Mars, respectively. GRAM-99, like prior versions of GRAM, implements an amalgamation of empirical models that represent geographical, seasonal, and monthly variations of the state of the terrestrial atmosphere (thermodynamic variables and horizontal and vertical wind components) at all altitudes from the ground up to those of spacecraft orbits. Mars-GRAM provides engineering estimates of density, temperature, pressure, and wind components in the Martian atmosphere as functions of latitude, longitude, altitude, and time.

Posted in: Briefs, Software, Mathematical models, Computer software and hardware, Weather and climate, Thermodynamics

Gyroscope Automated Testbed

The Gyroscope Automated Testbed (GAT) is a fully automated inertial device characterization testbed. Rotational response parameterization and shortterm noise stability analysis are the fundamental principles behind the system. Complete response characterization, bias stability, sensitivity, and range are supported along with a drift stability and noise analysis through use of a Green chart and calculation of the power spectral density. GAT is also capable of performing turn-on cycle stability and temperature-dependent testing.

Posted in: Briefs, TSP, Software, Computer software and hardware, Test equipment and instrumentation

Nanoelectronic Devices With Precise Atomic-Scale Structures

Field-effect transistors with nanometer dimensions are under development.

Since its invention in 1948, the transistor has revolutionized everyday life. The electronics revolution is based on miniaturization of transistors; smaller transistors are faster, and denser circuitry has more functionality. Transistors in the present generation of integrated-circuit chips have sizes of ≈0.18 µm, and the electronics industry has completed development of 0.13-µm transistors, which will enter production within the next few years. Industry researchers are now working to reduce transistor sizes below 0.1 µm — a thousandth of the width of a human hair. However, studies indicate that the miniaturization of silicon transistors will soon reach its limit.

Posted in: Briefs, Electronics & Computers, Downsizing, Integrated circuits, Transistors, Nanotechnology

Mounting Flip Chips on Heat-Dissipating, Matched-CTE Boards

Integrated-circuit chips can run cooler, and solder joints are less likely to fail.

“Flip chip on board (FCOB) with high thermal conductivity and tailored coefficient of thermal expansion (CTE)” denotes a developmental concept for relatively inexpensive, lightweight packaging of electronic circuits to accommodate high densities of components and of interconnections. The concept addresses several issues that pertain to flip-chip performance and reliability and to the integration of flip chips with other components: These issues include minimization of undesired mismatches of CTEs between flip chips and printed-wiring boards (PWBs), removal of heat from high-power flip chips, and the need to maximize stiffness while minimizing weight.

Posted in: Briefs, Electronics & Computers, Integrated circuits, Conductivity, Thermal testing

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