Tech Briefs

Protocols for Handling Messages Between Simulation Computers

Both time-critical and delivery-critical characteristics are accommodated. Practical Simulator Network (PSimNet) is a set of data communication protocols designed especially for use in handling messages between computers that are engaging cooperatively in real time or nearly real time training simulations. In a typical application, computers that provide individualized training at widely dispersed locations would communicate,by use of PSimNet, with a central host computer that would provide a common computational simulation environment and common data. Originally intended for use in supporting interfaces between training computers and computers that simulate the responses of spacecraft scientific payloads, PSimNet could be especially well suited for a variety of other applications — for example, group automobile driver training in a classroom. Another potential application might lie in networking of automobile diagnostic computers at repair facilities to a central computer that would compile the expertise of numerous technicians and engineers and act as an expert consulting technician.

Posted in: Briefs, TSP, Information Sciences, Computer simulation, Communication protocols, Data exchange


Statistical Detection of Atypical Aircraft Flights

A priori specification of search criteria is not necessary.

Posted in: Briefs, TSP, Information Sciences, Statistical analysis, Computer software and hardware, Data management, Crash prevention, Risk assessments


Developing Signal-Pattern-Recognition Programs

Software system aids development of application programs that analyze signals. An automated system to assist a General Aviation (GA) pilot in improving situational awareness of weather in flight is now undergoing development. This development is prompted by the observation that most fatal GA accidents are attributable to loss of weather awareness. Loss of weather awareness, in turn, has been attributed to the difficulty of interpreting traditional pre-flight weather briefings and the difficulty of both obtaining and interpreting traditional in-flight weather briefings. The developmental automated system not only improves weather awareness but also substantially reduces the time a pilot must spend in acquiring and maintaining weather awareness.

Posted in: Briefs, TSP, Information Sciences, Automatic pilots, Weather and climate, Business and general aviation aircraft


NASA's Aviation Safety and Modeling Project

Capabilities for automated analysis of flight data are under development. The Aviation Safety Monitoring and Modeling (ASMM) Project of NASA’s Aviation Safety program is cultivating sources of data and developing automated computer hardware and software to facilitate efficient, comprehensive, and accurate analyses of the data collected from large, heterogeneous databases throughout the national aviation system. The ASMM addresses the need to provide means for increasing safety by enabling the identification and correcting of predisposing conditions that could lead to accidents or to incidents that pose aviation risks.

Posted in: Briefs, TSP, Information Sciences, Computer software and hardware, Data management, Risk management, Crash prevention


Vaporizable Scaffolds for Fabricating Thermoelectric Modules

Thermoelectric legs would be separated by precise gaps. A process for fabricating thermoelectric modules with vacuum gaps separating the thermoelectric legs has been conceived, and the feasibility of some essential parts of the process has been demonstrated. The vacuum gaps are needed to electrically insulate the legs from each other. The process involves the use of scaffolding in the form of sheets of a polymer to temporarily separate the legs by the desired distance, which is typically about 0.5 mm. During a bonding subprocess that would take place in a partial vacuum at an elevated temperature, the polymer would be vaporized, thereby creating the vacuum gaps. If desired, the gaps could later be filled with an aerogel for thermal insulation and to suppress sublimation of thermoelectric material, as described in “Aerogels for Thermal Insulation of Thermoelectric Devices” (), NASA Tech Briefs, Vol. 30, No. 7 (July, 2006), page 50.

Posted in: Briefs, TSP, Materials, Fabrication, Insulation, Polymers, Electro-thermal engines


Interferometric System for Measuring Thickness of Sea Ice

Frequency- and spatial-domain VHF radar interferometry are used. The cryospheric advanced sensor (CAS) is a developmental airborne (and, potentially, spaceborne) radar based instrumentation system for measuring and mapping the thickness of sea ice. A planned future version of the system would also provide data on the thickness of snow covering sea ice. Frequent measurements of the thickness of polar ocean sea ice and its snow cover on a synoptic scale are critical to understanding global climate change and ocean circulation.

Posted in: Briefs, TSP, Physical Sciences, Radar, Environmental testing, Water, Weather and climate, Test equipment and instrumentation


Measuring Attitude of a Large, Flexible, Orbiting Structure

A document summarizes a proposed metrology subsystem for precisely measuring the attitude of a large and flexible structure in space.

Posted in: Briefs, TSP, Physical Sciences, Measurements, Attitude control, Satellites


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