Electrical/​Electronics

A relatively inexpensive, lightweight, durable, easy-to-operate radio-frequency (RF) instrument has been developed, along with special electromagnetic tags, for use in detecting buried objects to which the tags are attached. Each tag comprises a dipole antenna (basically, two collinear...

In a proposed method of designing a recon- figurable antenna, the design would be opt- imized through evolution in hardware. The proposed method would be a specific instance of an emerging general method of automated synthesis of electronic circuits in hardware. Other specific instances...

A test bench based on field-programmable gate arrays (FPGAs) has been developed to reduce the cost of testing nonvolatile memory circuits. Specifications for endurance testing of memories can require test times as long as weeks — often impractically long in the case of commercial memory...

A report discusses aspects of a ranging system in which the distance between the Earth and a spacecraft is determined from the difference between the phases of (1) modulation on a radio signal trans- mitted to the spacecraft and (2) a replica of the modulation transmitted back to Earth by a transponder on...

The Advanced Payload Transfer Measurement System (APTMS) comprises electromechanical sensors and sensor output-processing circuits. Designed specifically for measuring offsets between spacecraft payload trunnions and trunnion supports during ground-based payload-transfer operations, the APTMS could be...

This report examines design considerations in one of the most promising new areas of engineering – Micro Electro Mechanical Systems (MEMS). Designing and optimizing MEMS devices involves unique challenges, including analyzing the inter- dependent physical phenomena to which MEMS devices are sensitive and working...

A report presents additional information on the devices described in “Noise-Reducing Slots in Quantum-Well Infrared Photodetectors” (NPO-20518), NASA Tech Briefs, Vol. 25, No. 6 (June 2001), page 6a. To recapitulate: it was proposed that incorporation of suitably dimensioned crossed...

The Remote Monitoring and Alarm System (RMAS) is a system of electronic hardware and software for monitoring of fiber-optic video transmission equipment at Kennedy Space Center (KSC). The RMAS could also monitor other equipment that generates discrete contact closures and/or analog voltages. The hardware includes...

Failure-reporting devices somewhat similar to the “black box” data recorders on aircraft have been proposed. These devices were conceived for use on spacecraft, but might also be useful on terrestrial autonomous underwater vessels or terrestrial remote exploratory robots. The...

A computer program under continuing development strives to locate a safe landing site for a spacecraft through realtime processing of image data acquired by a video camera aimed at the terrain below while the spacecraft descends. The program might also be useful for aiding the selection of...

The hybrid electric-field sensor (HEFS) has been proposed for measuring quasi-static electric fields — especially those associated with thunderstorms. The HEFS would combine the relative compactness, low cost, and low power consumption of prior inductionprobe- type electric-field sensors with the higher sensitivity of...

Improved multiple-cavity ruby masers are under development for use as low-noise amplifiers (LNAs) for receiving very weak radio signals in frequency bands up to and including one centered approximately at 32 GHz. These masers were designed specifically to be incorporated into receivers in ground stations of...

The CCSDS Telemetry and Telecom Software Library provides a reference implementation of the Consultative Committee for Space Data Systems (CCSDS) international protocol standard for the transmission and reception of telemetry and telecommand data in radio communications with spacecraft. The library supports...

Parallel Telemetry Processor (PTEP) is a high-speed, robust, extensible, Javalanguage computer program that (1) enables the parallel processing of a serial stream of telemetric data and (2) generates a graphical display for monitoring the processing. Originally intended for application to spacecraft...

Multi-Mission Power Analysis Tool (MMPAT) is a computer program for constructing computational models of the generation, storage, consumption, and flow of electric power in a spacecraft. Heretofore, such modeling has been accomplished by means of unique software for each application. In contrast,...

A mathematical model that represents several physical and mental behaviors has been developed to enable the phenomenological description of basic functions of immune systems. This development is part of a continuing effort to improve the autonomy of robots and spacecraft by use of computational methods...

A report presents a theoretical and experimental study of amplification in electronic circuits that include combinations of discrete light sources (e.g., lightemitting diodes) and photodetectors (e.g., reverse-biased photodiodes), which combinations perform essentially the same functions as...

A technical report enunciates the concept of a hierarchy of sensor classes (meaning transducers, associated circuitry, and embedded software) that have different levels of intelligence, and discusses issues pertaining to the development of sensors of the highest level of intelligence, called cognitive. The other...