Showing papers on "Data acquisition published in 1974"

Automatic data acquisition method and system

Abstract: OF THE DISCLOSURE Continuous type analog data sampled at a high rate automatically is acquired in real time from data acquisition units, established at each of a plurality of spaced source stations. For example in seismic operations the units sense ground motion at spaced detector stations and convert resulting electrical signals to digital representations of such motion. A unique response code is set in each data acquisition unit. From a master station in or adjacent the prospect, data frame pulse sets are transmitted along with a series of channel sync pulses. At each unit digital representations of motion are stored upon receipt of each data frame pulse set. Sync pulses are received and counted at each unit following each data frame pulse set. The count of sync pulses at each said unit is decoded and compared with the respective response codes. In response to coincidence between each decoded count and re-sponse code, the stored signal is transmitted to the master station from each said unit.

Automation techniques for Raman spectroscopy

Abstract: This paper is concerned with the automation and control of grating spectrometers by digital techniques. The methods outlined include: a simple manually operated digital control; a dedicated logic system with data storage; data acquisition and control systems run by a computer in real-time and time-sharing modes. The performance of these methods is evaluated. A basic spectrometer control unit is described; this unit forms a module around which more general spectrometer control systems may be constructed.

Computer automated radar terminal system

Abstract: An automated radar terminal system employs primary (noncooperative) and secondary (cooperating transponder) surveillance radar equipment to monitor the ensemble of aircraft disposed within a subject air space. A data acquisition subsystem supplies detected and verified aircraft transponder-emitted beacon messages, and derived parameters which characterize each message such as aircraft range and azimuth, to a data processing subsystem. The central processor and memory structure there included maintain the interrelated target scratch pad, data base and multiple display files for accurately and efficiently presenting flexible combined primary radar video-alpha-numeric displays which typically vary at each of plural controller display stations.

On the Evaluation of Chemical Relaxation Measurements with Sampling Technique and On-Line Processing

Abstract: A relatively simple digitizing interface for use in chemical relaxation experiments is described. It is possible to sample by repeating the experiments and adding the data in a small on-line computer. This technique has considerably improved the accuracy obtainable in relaxation experiments as well as the speed of data acquisition. The relaxation data, which are corrected by the computer program for superimposed exponential decay processes of small amplitude, are available immediately after the experiment. By integrating the analog signal before digitization, nearly optimal electronic filtering is achieved. The technique has been extensively used in the pressure-jump technique but is applicable also to related methods. An example for the application to signals which do not change exponentially with time illustrates further possibilities of the proposed technique.

Computer controlled ENDOR spectrometer

Abstract: The design and construction of a computer-controlled X-band ENDOR spectrometer are described. The instrument operates in the RF band 3-39 MHz with a maximum power of 1 kW, corresponding to fields of 80 G peak to peak in the cavity. Details of a new construction for the microwave cavity are given. A minicomputer is used for control of the experiment and data acquisition, processing and display. Examples of the performance are presented.

Transformerless input for seismic data acquisition system

Abstract: In a long line data acquisition system, an input network is provided for coupling the lines to a data acquisition unit. The network includes the cascade combination of a first filter presenting a low pass frequency response to common mode voltage and a second filter presenting a low pass frequency response to difference mode voltage. The output of the second filter is coupled to an amplifier having high common mode rejection. The network substantially reduces, at the amplifier input, both common mode and difference mode noise picked up by the lines.

Moire' Patterns and Two-Dimensional Aliasing in Line Scanner Data Acquisition Systems

Abstract: The basic mechanism underlying the generation of Moire' patterns in line scanner data acquisition systems is examined. A general expression is developed in terms of typical system parameters for the reproduced image of such systems and the interaction of the image spectrum; the raster frequency and digital sampling frequency of the A/D conversion process are discussed and examples given. System design requirements for avoiding Moire' pattern generation and two-dimensional aliasing are discussed.

The effect of atmospheric water vapor on automatic classification of ERTS data

Abstract: Absorption by atmospheric water vapor changes the spectral signatures collected by multispectral scanners if channels are not chosen to avoid the atmospheric water bands. For ERTS (Earth Resources Technology Satellite), the Multispectral Scanner band 7 (MSS 7, .8 to 1.1 micron) is the only band significantly affected. Line-by-line atmospheric absorption calculations showed that this effect can multiply the intensity by factors ranging from .77 to 1.0. If horizontal gradients in atmospheric water exist between training fields and the rest of the scene, errors are introduced in automatic classification of the imagery. The degradation of the classification of corn and soybeans was determined by using actual ERTS data and simulating the absorption effects on the MSS 7 band.

All-sky photoelectric lightning detector apparatus

Abstract: A pair of position sensing photodiodes of a conventional quadrature or duaxis type are deployed face-upwardly at a predetermined distance one from the other. A vertically pointing fisheye lens covers each of the position sensing diodes so that the diodes view a full 360° in azimuth and about 180° in zenith angle. Each of the diodes produces four current outputs whose fractional distribution provides the location of the optical center of a luminous source, such as a lightning discharge. The outputs, in turn, are applied to a data acquisition system, such as a simple analog computer, which provides the location data for the lightning discharge as well as its total intensity. The circuit applying the outputs to the data acquisition system includes filtering means for eliminating background noises and passing to the system only the optical transients of the discharge.

Data acquisition system for spectrophotometer

Abstract: A data acquisition system for a spectrophotometer which comprises a pulse providing means for sequentially providing an established number of pulses to the stepping drive means of the spectrophotometer for sequentially moving the spectrophotometer's monochromator means to a plurality of test positions. The pulse providing means further provides output signals indicative of each of the test positions. The system also comprises an output means connected to said pulse providing means for providing sequential output signals representative of the spectrophotometer output signals at each test position.

Recent Advances in Internal Combustion Engine Instrumentation with Particular Reference to High-Speed Data Acquisition and Automated Test Bed

Abstract: The development of instrumentation techniques for research in internal combustion engines is described. A general discussion of instrument classification and requirements is followed by a description of transducer development including calibration techniques, signal processing, and data acquisition. Details are given of two direct on-line digitizing devices for high-speed data acquisition (one purpose made and the other using an on-line computer). An analysis of instrumentation and data acquisition errors is presented. The integration of the data acquisition equipment into a semi-automatic controlled test bed is described and a proposal for a fully automated test bed presented.

Optimization of chromatographic separations by computer control

Abstract: A system for optimizing gas chromatographic separations by computer control in real time is described. The GC-CPU interface controls the high precision sampling valve, temperature controller, flow controller, programmable gain amplifier, and time base. Algorithms for data acquisition, data reduction, and control are outlined. The criteria for optimization of the experimental conditions are based on peak symmetry, resolution, and relative retention. This approach is compared to other modes of control such as precolumn techniques, serial column switching, recycling columns, and library file searching.

Inexpensive Diode Thermometry Using Integrated Circuit Components

Abstract: Two temperature sensing circuits using silicon diodes and integrated circuit components are described. They are intended for use with data acquisition systems and are suitable for field or laboratory applications. Both can be constructed by persons without electronic training and have features of simplicity, low cost, and high accuracy.

An ultrasonic holographic imaging system for medical applications

Abstract: The application of ultrasonic holography to medicine has been suggested by many researchers as an alternative to the use of pulse-echo systems for medical diagnosis. This program has as an ultimate objective the development of a real-time holographic imaging system with digital image reconstruction and its evaluation for medical research. The present system configuration is such that, although in actual operation it does not constitute a real-time imaging system, in every other way one can evaluate its capabilities. Data acquisition, recording, and image reconstruction are performed under control of an Alpha-16 minicomputer. Image reconstruction is performed, however, off-line by a CDC 7 600 computer system. The system offers a variety of modes of operation. Holographic data may be collected by means of a piezoelectric sensing array, or may be modeled by means of digital computation. Although the system is being built with a particular array sensor, through the use of modeling, the performance of arrays with different elements and different spacings may be readily evaluated.

An instrumentation-orientated micro-computer: an extremely inexpensive data acquisition computer optimised for the automated laboratory

Abstract: The design and realisation of a maximally versatile multi-access on-line digital computer system for support of instrumentation design, experiment control and data interpretation in chemical research are discussed. Features included are (i) development of low-cost modular experiment control processors for installation in, and dedication to, laboratory-captive instrumentation systems, (ii) configuration and installation of a central multi-programmed computer system which serves as a common experiment-design, data analysis and mass-storage resource, (iii) current and proposed research of new varieties of computer-assisted experiment design techniques for the rapid implementation of instrumentation by research chemists and (iv) application of the complete system to a variety of chemical research environments representative of a broad range of instrumentation requirements. The modular experiment control processors (micro-computers) serve as remote, “intelligent” data acquisition terminals of the central system. Their design utilises recent developments in micro-circuit technology and the results of detailed analysis of the requirements of the research environment to achieve a unique level of cost-effectiveness.

The Optimum Design of a Tandem Computer Buffer in a System for Remote Data Collection

Abstract: It is anticipated that computer-communications systems designed for the purpose of transmitting data from geographically clustered terminals to a remote computer will employ multiplexing techniques in order to reduce transmission costs. A procedure is described for determining, under three criteria, the optimum computer buffer size assuming that the data traffic arriving at the multiplexer is Poisson and that the multiplexer and data link (transmission line) can, together, be represented by a constant-holding-time server. The approach taken is that since the computer is in tandem with the multiplexer and data link, we can make use of analytical results on the output process of an M/D/1 queueing system (the multiplexer and data link) in order to design the computer buffer. A comparison is made between the proposed procedure, the "worst case" designs, and other possible analytical approaches to the problem.

A Computerized Klinger Cavity Mode Conversion Test Set

Abstract: A mode conversion test set utilizing the klinger cavity technique has been developed for characterizing circular waveguide components in the millimeter waveguide region. The test set incorporates a precision linear displacement optical encoder and a specially designed controller which interfaces the test set to a Hewlett-Packard 2100 series computer. Control commands of a stored computer program are used by the operator for data acquisition and analysis. Experimental results show this system has high measurement accuracy and sensitivity while maintaining an uncomplicated measurement process.

Fast data acquisition system

Abstract: A data acquisition system for obtaining detailed information on fast, transient electrical signals The signal to be recorded is applied as a traveling wave to a longitudinally extending electro-optical modulator Light pulses are applied to a pluralilty of locations along one side of the modulator and modulated pulses representative of the intensity of the electrical signal at those locations received on the opposite side and further processed such as by conversion to digital

Data Acquisition and Processing for High-Resolution Mass Spectrometry Using a Small Nondedicated Computer Research sponsored by the U.S. Atomic Energy Commission under contract with the Union Carbide Corporation.

Abstract: A system has been developed to process data generated by a high-resolution mass spectrometer using a small computer. The computer is dedicated to the instrument only during data acquisition and is otherwise available for a variety of computational tasks in a general mass spectrometry laboratory. The programs include those to acquire the data directly from the mass spectrometer and store them on the computer disk storage device (written in assembly language); those to reduce the data on the disk to a table of exact masses and intensities, including deconvolution of multiplets (written in FORTRAN IV); and those to determine possible empirical formulas and fragmentation sequences for a given series of exact masses (also in FORTRAN IV). All observed PFK peaks are used as reference masses in an advancing subregion techinque that gives improved mass measuring accuracy.

State notation and SKED: A general system for control and recording of behavioral experiments

Abstract: State notation is a language for describing behavioral procedures and data acquisition formats. A minicomputer system has been developed for translating state notation into operating computer programs, which can control 10 simultaneous and independent experiments. A description of the system is provided, including the hardware necessary to interface the computer with the experimental environment

Analog to hybrid stereoplotter

Abstract: HYBRID STEREORESTITUTION SYSTEMS SEEM TO FIT BETWEEN CONVENTIONAL ANALOG AND MODERN DIGITAL OR ANALYTICAL STEREOPLOTTERS. WITH THE CURRENT TECHNOLOGICAL TREND TOWARDS ON-LINE USE OF COMPUTERS AND AUTOMATION, DIGITIZATION OF STEREOMODEL DATA, ITS PROCESSING AND OUTPUT IN REAL-TIME CAN ADVANTAGEOUSLY BE PUT UNDER COMPLETE COMPUTER, I.E., SOFTWARE, CONTROL. BESIDES THE DESIGN OF COMPLETELY NEW HYBRID SYSTEMS, THE AUTHORS ARE IN FAVOR OF PROPAGATING MODIFICATION AND UPGRADING OF EXISTING ANALOG PLOTTERS TO HYBRID SYSTEMS. REASONS FOR THIS ARE THE GENERAL AVAILABILITY OF ANALOG EQUIPMENT, THE IMPROVEMENT OF AN INSTRUMENT'S OVERALL PERFORMANCE, CONSIDERATION OF DETERMINISTIC ERRORS OR DISTURBANCES, SIMPLIFICATION OF ORIENTATION PROCEDURES, AND RESTITUTION OF NON-CONVENTIONAL PHOTOGRAPHS. SEVERAL DEVELOPMENT STAGES OF A RESEARCH PROJECT CARRIED OUT AT THE AUTHORS' DEPARTMENT ARE DESCRIBED, VIZ., ON-LINE DATA ACQUISITION SYSTEM, ON-LINE CONTROL OF AN XY-PLOTTER, ON-LINE PERIPHERAL BULK STORAGE, REAL-TIME FEEDBACK STEREORESTITUTION SYSTEM, AND TIME-SHARED CONTROL OF SEVERAL STEREOPLOTTERS. REAL-TIME CONTROL OF FIVE BASE COMPONENTS IN A UNIVERSAL STEREOPLOTTER IS PROPOSED.

MIDAS, prototype Multivariate Interactive Digital Analysis System, phase 1. Volume 1: System description

Abstract: The MIDAS System is described as a third-generation fast multispectral recognition system able to keep pace with the large quantity and high rates of data acquisition from present and projected sensors. A principal objective of the MIDAS program is to provide a system well interfaced with the human operator and thus to obtain large overall reductions in turnaround time and significant gains in throughput. The hardware and software are described. The system contains a mini-computer to control the various high-speed processing elements in the data path, and a classifier which implements an all-digital prototype multivariate-Gaussian maximum likelihood decision algorithm operating at 200,000 pixels/sec. Sufficient hardware was developed to perform signature extraction from computer-compatible tapes, compute classifier coefficients, control the classifier operation, and diagnose operation.

A computer-controlled, on-board data acquisition system for wind-tunnel testing

Abstract: A computer-controlled data acquisition system has been developed for the 40x80-foot wind tunnel at Ames Research Center. The system, consisting of several small onboard units installed in the model and a data-managing, data-displaying ground station, is capable of sampling up to 256 channels of raw data at a total sample rate of 128,000 samples/sec. Complete signal conditioning is contained within the on-board units. The sampling sequence and channel gain selection is completely random and under total control of the ground station. Outputs include a bar-graph display, digital-to-analog converters, and digital interface to the tunnel's central computer, an SEL 840MP. The system can be run stand-alone or under the control of the SEL 840MP.