Electrical/​Electronics

A lidar apparatus called a microaltimeter has been proposed for use aboard a spacecraft in orbit around the Earth for mapping land and sea surfaces, including such features of special interest as ice, tree canopies, and flood plains. The microaltimeter is short for "microlaser altimeter" and...

Ignitor and keeper power supplies have been developed specifically for a Hall-effect thruster with a cold cathode. Prior to the development of these power supplies, difficulties had been observed in the operation of cold-cathode Hall thrusters; in particular, they did not start reliably...

Range Safety Officers (RSOs) are used by NASA and other government agencies to assure protection of life and property during launch operations. The current decision-making system used by the RSOs at NASA Wallops Flight Facility (WFF) and the National Ranges, including the Eastern Range (ER) and Western...

Experiments have shown that a substrate can be patterned with submicron features by the following procedure:

An advanced technique of deep reactive-ion etching (DRIE) has been developed for fabricating smooth vertical walls in silicon wafers. These walls are suitable for use as bounding surfaces of optical waveguides in photonic and optoelectronic devices. The roughness of a typical 8-µm-high...

A previously developed apparatus that tracks the orientation of the human eye has been modified to make it less susceptible to error induced by ambient infrared light. The apparatus is a commercial product intended primarily for use as a computer-control interface for a person who is physically unable to use a...

Neural networks of a proposed type would be formed with computational units called "neuromorphs" attached in a locally connected array. These neural networks would achieve pattern recognition invariant under rotation and translation by exploiting a combination of network symmetry and...

Cross-correlated trellis-coded quadrature modulation (XTCQM) has been proposed as a generic scheme with specific embodiments that potentially offer superior alternatives to other highly power- and bandwidth-efficient phase-shift-keying (PSK) modulation schemes. Examples of such schemes include...

A low-power, miniature Doppler lidar instrument is being developed for use in measuring opacity (from dust) and wind profiles in the Martian atmosphere. The instrument could also be used on Earth to measure turbulence in the atmospheric boundary layer, for assessments of urban and regional air...

Improved passive temperature-compensating attenuators have been developed for use in processing radio signals at frequencies up to about 18 GHz. In general, temperature-compensating circuits and devices are needed to minimize (preferably, to eliminate) undesired temperature dependences of the...

Miners today use externally powered machines designed to be used by a single operator, the autonomous miner. Many companies offer computer-operated mining equipment that can be used for both high wall and underground applications. Programmable logic controls with ring laser gyroscopes and inclinometers...

A prototype dual-polarization microstrip patch rectenna dimensioned for an operating frequency of 8.51 GHz has been built to demonstrate a design concept for obtaining maximum output voltage from a rectenna of a given size. This rectenna contains nine square microstrip patch antenna elements in a...

An algorithm has been developed for a computer-based electronic system that would aid human ground controllers in monitoring data from sensors in the electric-power system of the International Space Station. Among other things, the algorithm encodes knowledge of human experts; thereby harnessing...

A portable electronic unit with no moving parts except button switches digitizes and stores a 48-hour record of the myoelectric activity of the stomach and heart as sensed via electrodes on the surface of the abdomen. Just as the more familiar electrocardiogram (ECG) is useful in diagnosing the condition of the heart,...