Electrical/​Electronics

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 system for indoor navigation of a mobile robot includes (1) modulated infrared beacons at known positions on the walls and ceiling of a room and (2) a cameralike sensor, comprising a wide angle lens with a position-sensitive photodetector at the focal plane, mounted in a known position and...

A computer program partly automates the analysis, classification, and display of waveforms represented by digital samples. In the original application for which the program was developed, the raw waveform data to be analyzed by the program are acquired from space shuttle auxiliary power...

A report discusses the technical background and design of the Navigator Global Positioning System (GPS) receiver — a radiation-hardened receiver intended for use aboard spacecraft. Navigator is capable of weak signal acquisition and tracking as well as much faster acquisition of...

"Ultra-BOC" (where "BOC" signifies "binary offset carrier") is the name of an improved generic design of microwave signals to be used by a group of spacecraft flying in formation to measure ranges and bearings among themselves and to exchange telemetry needed for these measurements....

A high-rate digital receiver (HRDR) implemented as a peripheral component interface (PCI) board has been developed as a prototype of compact, general- purpose, inexpensive, potentially mass-producible data-acquisition interfaces between telemetry systems and personal computers. The installation of this board in a...

A report presents additional details about parts of the program of research and development that is the topic of the immediately preceding article. The report em- phasizes those aspects of the program that pertain to the use of multiple uplink laser beams in a ground-to-spacecraft optical...

A report in the form of lecture slides summarizes the optical-communications program of NASA's Jet Propulsion Laboratory (JPL) and describes the JPL Optical Communications Telescope Laboratory (OCTL) and its role in the program. The purpose of the program is to develop equipment and techniques for...

An improved timing scheme has been conceived for operation of a scanning satellite-borne rain-measuring radar system.The scheme allows a real- time-generated solution,which is required for auto targeting. The current timing scheme used in radar satellites involves pre-computing a solution...

A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that can...

A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard real-time applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at...

Modules of additional drive circuitry have been developed to enhance the functionality of a family of commercially available positioning motors (Picomotor™ or equivalent) that provide linear motion controllable, in principle, to within increments ≤30 nm. A motor of this type includes a...