Electronics & Software

COMBUSTOR and CNOISE are computer codes that predict far-field noise that originates in the combustors of modern aircraft turbine engines — especially modern, low-gaseous-emission engines, the combustors of which sometimes generate several decibels more noise than do the combustors of older...

The Space Physics Data Facility (SPDF) Web services provides a distributed programming interface to a portion of the SPDF software. (A general description of Web services is available at http://www.w3.org/ and in many current software-engineering texts and articles focused on distributed programming.) The...

Parallel Adaptive Mesh Refinement Library (PARAMESH) is a package of Fortran 90 subroutines designed to provide a computer programmer with an easy route to extension of (1) a previously written serial code that uses a logically Cartesian structured mesh into (2) a parallel code with adaptive mesh refinement...

Multipath Simulator Taking into Account Reflection and Diffraction (MUSTARD) is a computer program that simulates effects of multipath propagation on received Global Positioning System (GPS) signals. MUSTARD is a very efficient means of estimating multipath-induced position and phase errors...

One of the software modules of the emergency-vehicle traffic-light-preemption system of the two preceding articles performs numerous functions for the central monitoring subsystem. This module monitors the states of all units (vehicle transponders and intersection controllers): It provides real-time access to the...

An important part of the emergencyvehicle traffic-light-preemption system summarized in the preceding article is a software module executed by a microcontroller in each intersection controller. This module monitors the broadcasts from all nearby participating emergency vehicles and intersections. It gathers...

A prototype wireless data-communication and control system automatically modifies the switching of traffic lights to give priority to emergency vehicles. The system, which was reported in several NASA Tech Briefs articles at earlier stages of development, includes a transponder on each...

Optoelectronic sensor systems are being developed for use in maintaining fixed relative orientations of two scientific- instrument platforms that are in relative motion. In the original intended application, the platforms would be two spacecraft flying in formation and separated by a long...

A report describes the history and the continuing evolution of an avionic system aboard the space shuttle, denoted the caution and warning system, that generates visual and auditory displays to alert astronauts to malfunctions. The report focuses mainly on planned human-factors-oriented...

A report proposes the use of waveforms having fractal shapes reminiscent of sawteeth (in contradistinction to conventional regular sawtooth waveforms) as reference signals for pulse-width modulation in control systems for thrusters of spacecraft flying in formation.

A recently conceived suite of object-oriented software metrics focus is on semantic aspects of software, in contradistinction to traditional software metrics, which focus on syntactic aspects of software. Semantic metrics represent a more human-oriented view of software than do syntactic metrics. The...

A report describes the development of software for a digital processor that operates in conjunction with a finite-impulse-response (FIR) chip in a spaceborne lidar altimeter.Processing is started by a laserfire interrupt signal that is repeated at intervals of 25 ms. For the purpose of...

Structural Design and Analysis Toolset is a collection of approximately 26 Microsoft Excel spreadsheet programs, each of which performs calculations within a different subdiscipline of structural design and analysis.

ThreeDView was developed primarily as a component of the Science Activity Planner (SAP) software, wherein it is to be used to display annotated images of terrain acquired by exploratory robots on Mars and possibly other remote planets. The images can be generated from sets of multiple-texture image...

Mathematical Solutions Toolset is a collection of five software programs that rapidly solve some common mathematical problems.

Statistical Analysis Toolset is a collection of eight Microsoft Excel spreadsheet programs, each of which performs calculations pertaining to an aspect of statistical analysis.