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Rotating magnetic field of bubble domain memory is used to obtain time-division multiplexing of bubble domain circuits into quadrants. Memory bits are assigned on bit-per-chip rather than bit-per-module basis; power is reduced by circulating only portion of bubbles at a time.
A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs.
A television multiplexing system which includes a circuit that inserts a digital codes sync signal and a digital code into a video signal for identifying the channel is described. The digital sync signal and the digital coded signals are generated by a single crystal controlled clock so that they are always in synchronism with each other. In demultiplexing the signals are utilized for shifting the digital coded signals into a shift register. The shift register, in turn, activates a decoder according to the code stored in the shift register for selecting the proper recording disk or receiver for storing the video signal.
When making photographs in X rays or gamma rays with a multiple-pinhole camera, the individual images of an extended object such as the sun may be allowed to overlap. Then the situation is in many ways analogous to that in a multiplexing device such as a Fourier spectroscope. Some advantages and problems arising with such use of the camera are discussed, and expressions are derived to describe the relative efficacy of three exposure/postprocessing schemes using multiple-pinhole cameras.
A scatter-hole X-ray camera has been designed and flown in a rocket to measure solar X radiation. Its distinguishing feature is that many single pin-hole images are allowed to overlap - a multiplexing approach that saves space, gives practical signal-to-fog ratio, and requires special object reconstruction techniques. It was possible to reconstruct the appearance of the dominant source of solar emission on the day of rocket flight with better than one arc minute resolution. The coronal X-ray region had the same general shape and intensity distribution as the associated calcium K-line region.
The Astrometric Multiplexing Area Scanner (AMAS) is an instrument designed to perform photoelectric long focus astrometry of small fields. Modulation of a telescope focal plane with a rotating Ronchi ruling produces a frequency modulated signal from which relative positions and magnitudes can be extracted. Evaluation instrumental precision, accuracy and resolution characteristics with respect to a variety of instrumental and cosmical parameters indicates 1.5 micron precision and accuracy for single stars under specific conditions. This value decreases for increased number of field stars, particularly for fainter stars.
The major purpose of this study is to determine the accuracy of visual interpretations of data from two different sensors (ERTS-1; ERIM's multiplexed SLAR) for the study of flooded shorelines. Uncomplicated and primarily visual interpretation techniques are employed. These methods are considered most readily available to officials of local and small regional organizations who may need rapid reconnaissance mapping and information for the organization of disaster relief. Assumptions concerning the timely receipt of such remotely sensed data by those directing the relief have been made. Generally, it is determined that ERTS-1 and SLAR data are complementary, especially with respect to the interpretation of urban or built-up areas which are flooded, and together they can provide the necessary information for guiding relief operations.
A direct-coupling experiment between a 5-micrometer photovoltaic mercury-cadmium telluride detector and a CCD multiplexer is reported. No detectable degradation in signal-to-noise ratio was experienced
A breadboard bypass control system was developed to control a battery comprised of 26 JPL-developed negative limited Ni-Cd cells. The system was designed to automatically remove cells from the circuit when their voltages exceeded a fixed limit on charge and fell below a fixed limit on discharge. Major components of the system consisted of a cell voltage monitor, a multiplexing circuit, and individual electromechanical relays for each cell. The system was found to function well in controlling the battery during a simulated 10-month MM-71 mission and a 2-month simulated low earth orbit cycling mission. A flight version of the bypass system was estimated to have a total parts count of 150 and total weight of 1.63 kg. When fully developed, the system shows promise for improving life and reliability of spacecraft batteries.
Signal-to-noise ratios and the amount of multiplexing gain achieved with a Michelson spectrometer during detector and background noise are studied. Noise caused by the warm background is found in 10 and 20-micron atmospheric windows in high resolution Fourier spectroscopy. An equation is derived for the signal-to-noise ratio based on the number of channels, total time to obtain the complete spectrum, the signal power in one spectral element, and the detector noise equivalent power in the presence of negligible background. Similar expressions are derived for backgrounds yielding a noise equivalent power to a spectral element, and backgrounds having flat spectra in the frequency range under investigation.
Tests were performed to evaluate the operating characteristics of the interface between the Space Lab Bus Interface Unit (SL/BIU) and the Orbiter Multiplexer-Demultiplexer (MDM) serial data input-output (SIO) module. This volume contains the test equipment preparation procedures and a detailed description of the Nova/Input Output Processor Simulator (IOPS) software used during the data transfer tests to determine word error rates (WER).
Some general properties of multiplexing optical systems for astronomical applications are described. The advantages and disadvantages which characterize Fourier and digitally encoded instruments when faced with any of ten sources of noise are discussed.
The purpose of the paper is to explore the ramifications of doing the multiplexing function in the digital domain and of using the microprocessor to replace the hardwired control logic which resides in the typical analog to digital converter. Two types of conversion (one working in parallel inputs, and one in sequential order) strategies are discussed where the microprocessor is in full control of the conversion. One advantage of using a digital multiplexor is that, contrary to an analog multiplexor, it does not degrade the fidelity of the conversion process.
Synchronous time division multiplexing is analyzed. Packets of information arrive at the system as a compound Poisson process, and are transmitted only during individual periodic intervals. Packet arrivals are blocked (lost) if the system has a finite capacity and is congested. Using the theory of semiregenerative processes, the distribution of the number of packets in the system (system size) is found. This nonstationary distribution is used to determine the complete system behavior, including the delay distributions, the blocking probability, and the density of the system size at arrival instants. Numerical examples illustrate applications of the results given.
Multiplexed extrinsic silicon detector arrays for infrared applications were developed and tested. Cryogenic electronics are discussed. Ambient temperature electronics are also discussed.
The multiplexer-demultiplexer (MDM) project included the design, documentation, manufacture, and testing of three MDM Data Systems. The equipment is contained in 59 racks, and includes more than 3,000 circuit boards and 600 microprocessors. Spares, circuit card testers, a master set of programmable integrated circuits, and a program development system were included as deliverables. All three MDM's were installed, and were operationally tested. The systems performed well with no major problems. The progress and problems analysis, addresses schedule conformance, new technology, items awaiting government approval, and project conclusions are summarized. All contract modifications are described.
Due to the conflicting demands of modern aircraft for increased systems/sensors and the decrease in cockpit panel size, weight, volume, and power, conventional discrete/dedicated methods of display and control are fast becoming obsolete. A means is sought to integrate the control and display into multifunctional programmable devices, thus giving the ability to increase system functions and yet conserve panel space. A potential solution to the control portion of the problem has come to be known as the Integrated Control Panel (ICP) approach. Flat panel display technology and controls using programmable flat panel displays with transparent capacitive touch control overlays offer the largest potential advantages. The flat panel display made of varistor-multiplexed dichroic liquid crystal (LCD) developed by GE in recent years appears to offer the ideal monochrome solution.
External, low-power alphanumeric label generator eliminates costly video circuitry. Microprocessor-based system for multiplexing alphanumeric and analog data stores both program and data. Uses inexpensive circuits, consumes minimal current, is programmable by user, adapts to many CRT monitors. System generates 5-by-7 dot-matrix characters. System speed is adaquate for medical monitoring purposes.