Information Technology & Software

Timeout Algorithm for Communications With Long Delays

Communications over long or intermittent links would be more efficient.

A query timeout detection algorithm has been proposed to support a protocol for reliable communications over links that are characterized by long delays because of (1) propagation of signals over interplanetary distances and/or (2) intermittency. The protocol could be an interplanetary analogue of Transmission Control Protocol/Internet Protocol (TCP/IP) of the terrestrial Internet. The protocol would enable the interconnection of the terrestrial Internet with the internets planned for Mars and other destinations in the Solar system. Potential beneficiaries include operators of space-exploration missions in the short term and commercial internet users in the long term.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Communication protocols, Internet, Communication protocols, Internet, Reliability, Reliability
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Generating Commands for the Mars Polar Lander Robotic Arm

A report discusses the use of the Web Interface for Telescience (WITS) for visualization and command sequence generation in the Mars Polar Lander (MPL) mission. WITS, which has been described in prior articles in NASA Tech Briefs, is an Internet-based software system that enables geographically dispersed scientists and engineers to participate in sequence generation for planetary lander and rover missions. Public outreach versions of WITS enable the general public to use WITS to view mission images and plan and simulate their own missions. WITS enables scientists to view mission data and generate command sequences from their home institutions, making it unnecessary for them to travel to a mission control center to participate in the mission. The present report describes how WITS fits in the MPL mission operations architecture and how it was used for Robotic Arm and Robotic Arm Camera sequence generation.

Posted in: Briefs, TSP, Information Sciences, Architecture, Communication protocols, Electronic control systems, Architecture, Communication protocols, Electronic control systems, Robotics, Spacecraft
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Advances in Parallel Computing on Adaptive Grids

Five papers address interrelated topics in parallel computing and the use of adaptive, unstructured computational grids. The titles of the papers and their general subject matters are the following:

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Data exchange, Data exchange, Technical reference, Technical review
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Coherent Phase Line Enhancer: a Method of Spectral Analysis

This method enables detection of weak signals that would otherwise be masked by noise.

The term "coherent phase line enhancer" (CPLE) refers to a dual-transform method of spectral analysis that enhances the detection of periodic and quasi-periodic signals buried in wide-band noise. The CPLE is particularly useful for increasing the signal-to-noise ratios of spectral peaks ("lines") that represent periodic and quasi-periodic components of measurements of vibration, dynamic strain, and/or dynamic pressure in a turbine or other rotating machine. The purpose of such measurements, spectral analysis, and enhancement of spectral peaks is to assess machine performance and identify spectral signatures of bearing or gear-train defects.

Posted in: Briefs, Information Sciences, Failure analysis, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Noise, Noise, Bearings, Gears
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Software for Secure Distribution of Data

Many users at remote locations can work on the same set of data.

MECS is a computer program for the automated, secure, rapid, and efficient transfer of data between a central source and users at multiple distant locations. "MECS" signifies "Multi-mission Encrypted Communication System." MECS enables many users to collaborate securely on a shared plan or set of data.

Posted in: Briefs, TSP, Information Sciences, Computer software / hardware, Computer software and hardware, Cyber security, Data exchange, Computer software / hardware, Computer software and hardware, Cyber security, Data exchange
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Common Database Interface and Report Generator

This program yields reusable, centralized code.

The Common Database Interface and Report Generator is a computer program that serves as both (1) a single common interface for data-base application programs to gain access to local or remote data bases by use of Structured Query Language (SQL) operators and (2) a report generator.

Posted in: Briefs, TSP, Information Sciences, Computer software / hardware, Computer software and hardware, Data exchange, Computer software / hardware, Computer software and hardware, Data exchange
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General-Purpose Wavelet Program

This program affords a variety of capabilities that are especially useful in wavelet analysis.

"S+Wavelets" is the name of a computer program that implements a suite of mathematical "tools" for wavelet analysis of signals (including two-dimensional signals that represent images.) Wavelets, being localized in both time and frequency (or space and wave number), serve as means for transforming and extracting information from signals that have temporally or spatially varying properties. In a sense, wavelet methods combine the best features of time and frequency methods (e.g., Fourier-transform methods). Modern wavelet research began in the mid-1980s, but until now, there has been no commercially available, general-purpose software to support rapid prototyping for research on, and application of, wavelets. S+Wavelets satisfies the need for such a computer code.

Posted in: Briefs, Information Sciences, Physical Sciences, Mathematical analysis, Rapid prototyping, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization
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Automated Generation of Reports of Mars Rover Operations

A document describes a system for the automated generation of reports of operations of a robotic exploratory vehicle (rover) on Mars. The automated report-generation system supplants a predominantly manual system, thereby making more information available in less time and reducing the probability of data-entry errors. The automated report-generation system has been incorporated into the Web Interface for Telescience, WITS, and utilizes information in the WITS database. (Described in several prior NASA Tech Briefs articles, the WITS is an Internet-based software system that enables geographically dispersed scientists and engineers to monitor and command a rover.)

Posted in: Briefs, TSP, Information Sciences, Internet, Internet, Data management, Documentation, Robotics, Spacecraft
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Algorithms for Recognition of Objects in Color Stereo Images

Objects of known size, shape, and color can be recognized in real time.

Algorithms have been developed to enable a robotic vision system to recognize, in real time (at a rate between 0.5 and 2 frames per second), known objects lying on the ground. In the original intended application, the algorithms would be executed by off-the-shelf computer hardware aboard a robotic vehicle that would traverse military ordnance-testing ranges to search for unexploded bombs. A stereoscopic pair of color video cameras aboard the vehicle would acquire images of the terrain near the vehicle, and the algorithms would process the digitized images to recognize the bombs by their known size, shape, and color. The algorithms may also be adaptable to other, similar robotic-vision applications — for example, automated recognition of color traffic signs for alerting drivers in automobiles.

Posted in: Briefs, TSP, Information Sciences, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Robotics
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A Metric for Visual Quality of Digital Video

This metric is based partly on human visual processing and is computationally efficient.

DVQ (which stands for "digital video quality") is a metric for evaluating the visual quality of digitized video images. Other video-quality metrics have been proposed, but it appears that each of them (1) may be based on mathematical models that are not related closely enough to the characteristics of human perception, in which case it may not measure visual quality accurately; or (2) may entail such large amounts of memory or computation that the contexts in which it can be applied are restricted. In contrast, DVQ was developed in an effort to incorporate mathematical models of human visual processing while maintaining computational efficiency so that accurate metrics can be computed in real time by use of modest computational resources.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Imaging, Imaging and visualization, Imaging, Imaging and visualization
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