Electronics & Software

FWH2D is a Fortran 90 computer program that solves a two-dimensional (2D) version of the equation, derived by J. E. Ffowcs Williams and D. L. Hawkings, for sound generated by turbulent flow. FWH2D was developed especially for estimating noise generated by airflows around such approximately 2D...

AutoChem is a suite of Fortran 90 computer programs for the modeling of kinetic reaction systems. AutoChem performs automatic code generation, symbolic differentiation, analysis, and documentation. It produces a documented stand-alone system for the modeling and assimilation of atmospheric chemistry. Given databases of chemical reactions...

Some improvements have been made in the formulation of holographically formed polymer-dispersed liquid crystals (H-PDLCs) and in the fabrication of devices made from these materials, with resulting improvements in performance. H-PDLCs are essentially volume Bragg gratings. Devices made from HPDLCs function as...

The Modulation Sideband Technology for Absolute Range (MSTAR) architecture is the basis of design of a proposed laser-based heterodyne interferometer that could measure a range (distance) as great as 100 km with a precision and resolution of the order of 1 nm. Simple optical interferometers...

A method has been formulated to enable prediction of the amount of work that remains to be performed in developing flight software for a spacecraft. The basic concept embodied in the method is that of using an idealized curve (specifically, the Weibull function) to interpolate from (1) the...

A recently developed data-compression method is an adaptive technique for coding quantized wavelet-transformed data, nominally as part of a complete image-data compressor. Unlike some other approaches, this method admits a simple implementation and does not rely on the use of large code tables.

An algorithm analyzes rain-gauge data to identify statistical outliers that could be deemed to be erroneous readings. Heretofore, analyses of this type have been performed in burdensome manual procedures that have involved subjective judgements. Sometimes, the analyses have included...

NASA's Jet Propulsion Laboratory (JPL) generates planetary and lunar ephemeris data and FORTRAN routines that allow users to obtain state data for the Sun, the moon, and the planets. The JPL Solar System Ephemeris Toolbox, developed at Kennedy Space Center, is a set of functions that provides the same functionality in...

Major upgrades have been made in two of the programs reported in "Five Computer Codes for Analysis of Turbomachinery" (LEW-16851), NASA Tech Briefs, Vol. 23, No. 11 (November 1999), page 28. The affected programs are:

An end-of-life prediction system developed for electric machines and their loads could be used in integrated vehicle health monitoring at NASA and in other government agencies. This system will provide on-line, real-time condition assessment and end-of-life...

A computer program has been written to facilitate appraisals according to the methodology of Capability Maturity Model Integration (CMMI). [CMMI is a government/ industry standard, maintained by the Software Engineering Institute at Carnegie Mellon University, for objectively assessing the engineering capability...

Wing-Viewer is a computer program for acquisition and reduction of image data acquired by any of five different scientific grade commercial electronic cameras used at Langley Research center to observe wind-tunnel models coated with pressure or temperature-sensitive paints (PSP/TSP).

The Grid Visualization Tool (GVT) is a computer program for displaying the path of a mobile robotic explorer (rover) on a terrain map. The GVT reads a map-data file in either portable graymap (PGM) or portable pixmap (PPM) format, representing a gray-scale or color map image, respectively.

An updated version of the General Chemical Kinetics and Sensitivity Analysis (LSENS) computer code has become available. A prior version of LSENS was described in “Program Helps to Determine Chemical-Reaction Mechanisms” (LEW-15758), NASA Tech Briefs, Vol. 19, No. 5 (May 1995), page 66. To...

Avionics System Architecture Tool (ASAT) is a computer program intended for use during the avionics-system-architecture- design phase of the process of designing a spacecraft for a specific mission.

TURBO-AE is a computer code that enables detailed, highfidelity modeling of aeroelastic and unsteady aerodynamic characteristics for prediction of flutter, forced response, and bladerow interaction effects in turbomachinery.

The Portable Airborne Laser System (PALS) is a combination of laser ranging, video imaging, positioning, and data-processing subsystems designed for measuring the heights of forest canopies along linear transects from tens to thousands of kilometers long. Unlike prior laser ranging...

A process for n-type (electron-donor) delta (d) doping has shown promise as a means of modifying back-illuminated image detectors made from n-doped high-purity silicon to enable them to detect high-energy photons (ultraviolet and x-rays) and low-energy charged particles (electrons and ions)....

Advanced ablative (more specifically, charring) materials that provide temporary protection against high temperatures, and advanced methods of designing and manufacturing insulators based on these materials, are undergoing development. These materials and methods were conceived in an effort to...