Special Coverage

Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
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

Real-Time Optoelectronic Particle-Fallout Monitors

These instruments would extract quantitative data from images of particles.

Optoelectronic instruments for real-time, in situ monitoring of particle fallout are undergoing development. Settings in which these instruments could prove useful include clean rooms for assembly of optical and electronic equipment, food-packaging facilities, and other industrial facilities in which one seeks to prevent contamination of products by airborne dust and fibers.

Posted in: Briefs, Test & Measurement, Optics, Optics, Particulate matter (PM), Test equipment and instrumentation

Program for Controlling Digital Instrumentation Recorders

A computer program enables the simultaneous monitoring and control of two commercial digital instrumentation recorders, each comprising a variable-rate buffer and a data tape recorder. The program can issue all standard tape-motion-related commands (fast forward, rewind, record, forward, reverse, and eject) plus commands for tape search, time code, and buffer settings. The program provides a graphical user interface that facilitates control by the user and displays the operational statuses of the buffers and tape recorders. The program generates a log file that includes a time and date stamp for each control command sent to, and response received from, each buffer and recorder. An option exists in the program to produce tape copies by dubbing from one recorder to the other. The program can also be used to effect a procedure in which data are recorded first on one tape recorder, then the other tape recorder is brought into operation shortly before the end of first tape, so that there is some overlap to ensure continuous recording during a long recording session.

Posted in: Briefs, Test & Measurement, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Human machine interface (HMI), Displays, Displays, Test equipment and instrumentation

Program Computes Tone Fan Noise From a Turbofan Engine

TFaNS is a computer program that predicts the tone noise that emanates from the fan stage of a turbofan engine. With the help of this program, engineers working to reduce fan tone noise can study the effects of proposed design changes and are thus more likely to be successful in their efforts.

Posted in: Briefs, Software, Sound quality, Sound quality, Fans, Turboprop engines

Software for Generating 100-by-100-km Images From SAR Data

SAR Processing System Precision Processor (SPS PP) is one of the computer programs used in the Alaska SAR Facility (ASF) [where "SAR" means "synthetic-aperture radar"] to generate image data products. SPS PP ingests data that have been received from the RADARSAT (a Canadian Earth-observation satellite) and decoded into engineering and SAR signal data files, and processes these data into image data products that typically cover areas of about 100 km by 100 km. SPS PP can handle data from RADARSAT standard right- and left-looking beams, and is being enhanced to handle European Remote Sensing Satellite (ERS) and Japanese Earth Resources Satellite (JERS) data. The output of SPS PP conforms to the standards of the Committee on Earth Observing Satellites (CEOS). The left-looking products feature 16-bit detected pixels in slant-range format; the right-looking products can be in either ground-range detected or slant-range complex format. SPS PP resides on five IBM SP-2 computers with 8 processing nodes each. Each computer can produce a 100-by-100-km image frame in about 25 minutes.

Posted in: Briefs, TSP, Software, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Radar, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Radar, Satellites

Sequencing and Job-Control Software for Processing SAR Data

The SAR Processing System Control Processor (SPS CP) computer program performs sequencing and job-control functions within the Alaska SAR Facility (ASF) [where "SAR" means "synthetic-aperture radar"]. SPS CP interacts with the Product-Distribution-and-Management (PDM) system of the ASF to receive processing orders as well as engineering and raw signal data. SPS CP provides a graphical user interface for operator control and performs job-sequencing functions to orchestrate the Raw Data Scanners (RDS) and SAR processors of the ASF to produce image data products. It is capable of displaying images to support visual data-product-quality checks. It is capable of recovering from errors caused by various abnormal processing events. The interfaces between SPS CP and the raw-data scanners and SAR processors are based on a client-server model with sockets and multithreading. SPS CP is hosted on SGI Origin or Challenge computers; the interfaces with raw data scanners and SAR processors are hosted on SGI Challenge, DEC Alpha, IBM SP-2, and Compaq computers. This program has been supporting ASF operations for over five years and its capabilities have been continuously enhanced to enable both large and small scientific-processing campaigns that have included mapping of the Amazon rain forest, the Antarctic Mapping Mission, and the Arctic Snapshot Mission.

Posted in: Briefs, TSP, Software, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Radar, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Radar, Weather and climate

Software for Processing RADARSAT ScanSAR Data Into Images

SAR Processing System ScanSAR Processor (SPS SSP) is a computer program that is used in the Alaska SAR Facility (ASF) to processes scanSAR downlink data from the RADARSAT (a Canadian Earth-observation satellite) into a suite of image data products. ["SAR" means "synthetic-aperture radar" and "scanSAR" means "scan-mode SAR."] SPS SSP can process data that have been generated in any of the four RADARSAT scanSAR modes in current use — two wide-swath modes (300 ≤ width ≤ 500 km) called "SWA" and "SWB" and two narrow-swath modes (width ≈ 300 km) called "SNA" and "SNB." The output images are projected in ground range or else geocoded in universal transverse Mercator, polar stereographic, or Lambert coordinates. At present, the only image data products that are calibrated are those of the SWB mode. Typically, an SWB image covers an area of about 500 by 500 km. SPS SSP is executed on an IBM PS-2 computer, which includes (1) a control workstation equipped with 128MB of random-access memory (RAM) and a 4GB hard disk and (2) as many as eight processing nodes, each equipped with 256MB of RAM and a 4GB hard disk. When all eight nodes are used, a typical SWB image frame can be computed in about 35 minutes.

Posted in: Briefs, TSP, Software, Architecture, Computer software / hardware, Computer software and hardware, Data exchange, Radar, Satellite communications, Architecture, Computer software / hardware, Computer software and hardware, Data exchange, Radar, Satellite communications

Software for Wafer-Level Testing of Microfabricated Devices

Prober Assistant Measurement System (PAMS) is a computer program that automates the time-consuming process of testing microfabricated devices (integrated circuits and/or microelectromechanical systems) at the wafer level. PAMS was written specifically for use with the Karl Suss probe station (a commercially available wafer-testing apparatus) and is compatible with associated testing circuitry that conforms to the IEEE 488 general-purpose interface bus (GPIB) standard. Manual wafer testing is tedious and susceptible to error because the process involves controlling the probe station to position the probe leads on each device, configuring the associated testing equipment, and recording the measurement data. In contrast, PAMS automatically positions the probe leads according to a wafer map and automatically performs the measurement and recording steps. Multiple devices on a wafer can be tested simultaneously, or multiple measurements can be made on a single device. Acquired data can be displayed on a screen and/or recorded in a file. At present, PAMS is executed on a computer based on a Pentium II processor with a clock rate of 400 MHz, 128MB of random-access memory, and 6GB of hard-disk storage, and running the Windows NT operating system.

Posted in: Briefs, TSP, Software, Computer simulation, Integrated circuits, Microelectricmechanical device, Microelectromechanical devices, Integrated circuits, Microelectricmechanical device, Microelectromechanical devices, Test procedures

RS Forward Error Correction for Variable-Length Frames

Method accommodates dynamically varying frame length.

A method of forward error correction by Reed-Solomon (RS) coding has been devised to increase the link margins of data-communication systems that must handle variable-length frames or packets of data. Heretofore, RS coding has involved fixed-length blocks: In order to encode variable-length frames, it has been necessary to (a) choose a fixed block length equal to a multiple of some given block length and greater than or equal to the length of the longest variable-length frame and (b) in the case of a frame shorter than the fixed block length, pad or fill the remainder of the block with extra bytes. This is very inefficient because the fill conveys no useful information, and any errors in the fill diminish the overall coding gain by using up some or all of the available error-correction capacity.

Posted in: Briefs, Information Sciences, Communication protocols, Data exchange, Communication protocols, Data exchange

Fast NRZLM Encoding and Decoding Algorithm

Byte-oriented algorithms save time.

A recently developed algorithm saves encoding and decoding time in the operation of data-communication systems that utilize the NRZM code, which is derived from the better-known non-return-to-zero-level (NRZL) code. This algorithm utilizes lookup tables that contain the results of routine encoding and decoding computations that would otherwise have to be performed repeatedly.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Communication protocols, Cryptography, Communication protocols, Cryptography

Polyaniline Compounds for Protection Against Corrosion

Protective surface layers can be formulated and applied in various ways.

Corrosion of iron and steel substrates can be inhibited by coating them with any of the wide variety of compounds denoted generally as polyanilines. A polyaniline suitable for this type of application can be in either an electrically conductive salt (doped) form or an electrically nonconductive base form. Typically, polyaniline is dissolved in an organic solvent and the resulting solution is applied to a substrate by spraying, dipping, or brushing. The solvent is then allowed to evaporate leaving the substrate coated with a solid film of polyaniline, typically 1 to 200µm thick.

Posted in: Briefs, TSP, Materials, Coatings Colorants and Finishes, Coatings, colorants, and finishes, Corrosion resistant alloys, Iron, Polymers, Steel

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