Showing papers on "Data acquisition published in 1999"

A comparison between photogrammetry and laser scanning

Abstract: A comparison between data acquisition and processing from passive optical sensors and airborne laser scanning is presented. A short overview and the major differences between the two technologies are outlined. Advantages and disadvantages with respect to various aspects are discussed, like sensors, platforms, flight planning, data acquisition conditions, imaging, object reflectance, automation, accuracy, flexibility and maturity, production time and costs. A more detailed comparison is presented with respect to DTM and DSM generation. Strengths of laser scanning with respect to certain applications are outlined. Although airborne laser scanning competes to a certain extent with photogrammetry and will replace it in certain cases, the two technologies are fairly complementary and their integration can lead to more accurate and complete products, and open up new areas of application.

Matching spatial data sets: a statistical approach

Abstract: Although the acquisition and maintenance of spatial data is very costly and time consuming very often the same objects of the real world are captured in many different data models, at different acquisition times, with different quality characteristics or at different scales. This situation will become intensified when more and more digital spatial data are offered by using internet technologies. Integration methods are needed to take advantage of the characteristics of more than one data set. These advantages could be, for example, new applications for which the data models had not been originally designed, higher reusability, improvement of the quality, or cost minimization of data acquisition. In this paper a relational matching approach for integration of spatial data from different sources is introduced. The research work was performed on street centrelines which were captured in different data models. The approach is based on statistical investigations between the data of two data models, and can be ...

Structured-light, triangulation-based three-dimensional digitizer

Abstract: The present invention provides a system for illuminating an object with a special kind of structured light pattern, recording the shape of the reflected points of light by means of a camera, and, by a triangulation technique that does not depend on the fixed direction of the light source relative to the camera, reconstructing the 3D shape of the object through a computer using the data points collected from the reflection of the structured light pattern. The scanning system is portable and does not require data processing contemporaneous with the data collection. The portable system stores in the storage media several images of the objects with different illumination patterns. The data is subsequently processed, by a computer system which applies data processing routines, i.e., the model building algorithms which provide 3D surface generation. The data acquisition according to the present invention is simplified to acquiring of only two or, optionally, four images of the object, thereby significantly increasing the digitization speed over that of laser-based scanners. The light source projects both structured light and uniform illumination light from the same apparent source, and that allows for numerical normalization of the images.

A microcontroller-based data acquisition system for solar radiation and environmental monitoring

Abstract: The hardware design and operation of a battery-powered microcontroller-based data acquisition system (DAS) for unattended remote measurements are presented. The system was designed around the ST62E20 8-bit microcontroller and applied for solar radiation monitoring. The measurement system uses the SolData silicon-cell pyranometer as the solar radiation sensor. The data from the sensor is collected by means of on-chip A/D converter and stored in a serial EEPROM until uploaded to a portable computer. Keeping the DAS in a low-power mode, which is only interrupted when measurements are to be taken or when a computer is connected to retrieve the stored data, minimizes power consumption. An on-chip timer provides an interrupt to awaken the system from its low-power wait mode at 10-min intervals to sample and store the data. At the end of each data collection period, the acquired data will be transmitted to the computer through the RS232 serial port for subsequent analysis. Only unprocessed data is stored in EEPROM. Quality control and data analysis is done off-line in the laboratory to minimize system cost, complexity and system downtime. Field tests and comparisons of this measurement system against the standard Eppley precision spectral pyranometer (PSP) have shown a slightly nonlinear correlation and that the accuracy of this measurement system as applied to solar radiation monitoring is fairly good, typically /spl plusmn/13 W/m/sup 2/.

Nonactive antenna compensation for fixed-array microwave imaging. II. Imaging results

Abstract: For pt. I see ibid., vol. 18, no. 6, p. 496 (1999). Model-based imaging techniques utilizing microwave signal illumination rely heavily on the ability to accurately represent the wave propagation with a suitable numerical model. To date, the highest quality images from the authors' prototype system have been achieved utilizing a single transmitter/single receiver measurement system where both antennas are manually repositioned to facilitate multiple illuminations of the imaging region, thus requiring long data acquisition times. In an effort to develop a system that can acquire data in a real time manner, a 32-channel network has been fabricated with all ports capable of being electronically selected for either transmit or receive mode. The presence of a complete array of antenna elements at data collection time perturbs the field distributions being measured, which can subsequently degrade the image reconstruction due to increased data-model mismatch. Incorporating the nonactive antenna-compensation model from Part I of this paper into the authors' hybrid element near field image reconstruction algorithm is shown to restore image quality when fixed antenna-array data acquisition is used. Improvements are most dramatic for inclusions located in near proximity to the antenna array itself, although cases of improvement in the recovery of centered heterogeneities are also illustrated. Increases in the frequency of illumination are found to warrant an increased need for nonactive antenna compensation. Quantitative measures of recovered inclusion shape and position reveal a systematic improvement in image reconstruction quality when the nonactive antenna-compensation model is employed. Improvements in electrical property value recovery of localized heterogeneities are also observed. Image reconstructions in freshly excised breast tissue illustrate the applicability of the approach when used with the authors' two-dimensional microwave imaging system.

Introduction to Real-time Control using LabVIEW TM with an Application to Distance Learning*

Abstract: This paper presents the approach taken to give engineering students the necessary competencies and facilities to implement real-time control solutions. This goal is achieved first by way of an introduction to the basic principles underlying real-time control. Then, by motivating the use of personal computers as a versatile alternative to more traditional implementation equipment. Finally, by combining LabVIEW and DAQ boards to form an integrated framework for fast prototyping of real-time control solutions. Control algorithms written in G (the graphical programming language of LabVIEW), in C or as S-functions (MATLAB scripts describing SIMULINK dynamical models) can be validated on laboratory-scale processes. The possible real- time control and monitoring of ongoing operations, either locally on the host computer or remotely via the Internet, is a key feature from an educational point of view. In fact, the chosen paradigm truly enable the `learning by doing' approach. Moreover, this practical activity can be carried out at any time from anywhere to efficiently support automatic control study.

Quality control for functional magnetic resonance imaging using automated data analysis and Shewhart charting.

Abstract: A data acquisition and analysis protocol for quality control (QC) of functional magnetic resonance imaging studies is presented. Two sets of data are acquired, single-timepoint data for measurement of signal-to-ghost and signal-to-noise ratios, and multiple-timepoint data for measurement of short-term drift. Since manual data analysis can be time consuming and an impediment to regular QC, an automated data processing scheme is presented. The use of automated Shewhart charting is proposed to identify significant changes in each parameter over the long term. The protocol has successfully identified system faults and deteriorations undetected by conventional QC.

Methods and apparatus for monitoring and controlling oil and gas production wells from a remote location

Abstract: The invention provides apparatus and methods for monitoring and controlling hydrocarbon production wells and/or injection wells from a remote location. The apparatus for monitoring and controlling one or more hydrocarbon production wells or injection wells from a remote location comprises one or more surface control and data acquisition systems; one or more sensors disposed in communication with the one or more control and data acquisition systems; one or more downhole flow control devices disposed in communication with the one or more control and data acquisition systems; and one or more remote controllers disposed in communication with the one or more control and data acquisition systems. Preferably, the remote controller comprises a computer having an internet access disposed in communication with the one or more control and data acquisition systems through a communication device comprising an internet web site server. The method for monitoring and controlling a downhole hydrocarbon production well or an injection well comprises: transmitting data collected by a downhole sensor module to a control and data acquisition system; evaluating downhole operating conditions and optimizing downhole operating parameters utilizing an optimization software program disposed in communication with the control and data acquisition system; and transmitting signals between the control and data acquisition system system and a remote controller utilizing a satellite communication system, the remote controller comprising a computer and an internet browser control access adapted to display operating conditions and parameters and to accept instructions to change operating parameters.

Industrial automation system and method for efficiently transferring time-sensitive and quality-sensitive data

Abstract: The system and method of industrial automation provides improved network transfer of data between nodes. The system comprises a plurality of computer systems which are interconnected through a network, wherein each of the computer systems executes industrial automation software. One or more of these computer systems interface to various hardware I/O devices for data acquisition. Each computer system is home to one or more client and/or server processes. Before data acquisition begins, every server process registers a plurality of time/quality (TQ) groups, wherein each TQ group is identified by a time/quality identification value (TQID), and wherein each TQ group represents a set of associated data elements. When a hardware I/O device generates data, a server process which is linked to that device through a device driver receives a block of data from the device. The driver assigns to the block a single timestamp and a single quality value. Using a real-time protocol, the server adds one or more blocks of data to a packet and transmits the packet to every client which has subscribed to the data. For increased network and computational efficiency, the real-time protocol includes compression techniques and is exception-based: only changed data elements, changed timestamps, and changed quality values are sent to clients. Both the clients and the server store the TQID for each block, so that the client can more efficiently update the changed timestamps and changed quality values for all data elements in a TQ group.

The general purpose data acquisition system MBS

Abstract: The GSI data acquisition system MBS (Multi Branch System) has become, since its introduction in 1994, the standard system at GSI (37 active systems+9 portable systems). It is also used at numerous outside laboratories (29 systems active). The current version MBS 2.2 will be replaced by the version 3.0, which contains three major enhancements. First, the data busses are no longer restricted to address mapped devices. It allows now also the usage of message oriented busses, like Ethernet (100 Mbit, Gigabit) or ATM. Second, a data acquisition system can now be configured with multiple event builders to increase the overall data rate on output devices. Third, a graphical user interface, written in Java has been implemented.

Improving data acquisition for fast-scan cyclic voltammetry

Abstract: Described is an improved data acquisition system for fast-scan cyclic voltammetry (FSCV). The system was designed to significantly diminish noise sources that were identified in previously recorded FSCV measurements for the detection of neurotransmitters. Minimized noise is necessary to observe the low concentrations of neurotransmitters that are physiologically important. The system was based on a high-speed, 16-bit AD/DA acquisition board that allowed high scan rates and better resolved the small faradaic currents which remained after background subtraction.Irregularities that occur when independent timing sources are used for generation of the voltage waveform and collection of the current can create large noise artifacts near the voltage limits during FSCV. These were eliminated by the use of a single acquisition board that generated the voltage waveform and collected the current. Noise from frequency drift of the power line was eliminated through the use of a phase-locked loop. To demonstrate the imp...

Design and implementation of a fuzzy logic computer-controlled sun tracking system

Abstract: This paper considers design and implementation of a computer-controlled sun tracking system to enhance the power output of photovoltaic (PV) solar panels. The tracking system is driven by two permanent magnet DC motors to provide motion of the PV panels in two axes. The control of the dual axis tracking system is not an easy task due to nonlinear dynamics and unavailability of the model parameters. Therefore, a PC-based fuzzy logic control algorithm utilizing the knowledge of the system behavior is designed in order to achieve the control objectives. The implementation of such a controller is realized by building an interfacing card consisting of sensor data acquisition, motor driving circuits, signal conditioning circuits and serial communication with the PC. A set of laboratory demonstrations shows the capability of the system to track the sun effectively.

Method for managing a heterogeneous IT computer complex

Abstract: The present invention provides a method for optimizing an IT environment, the method incorporating relational databases in conjunction with unique data acquisition and querying techniques providing a flexible query feedback of IT software, hardware and network parameters.

Crop yield monitoring system

Abstract: A peanut combine towed and powered by a tractor during harvesting includes a collection basket having a basket support frame mounted on the top of the combine by four load cells. A respective load cell is located beneath each lower bottom corner of the base of the collection basket between the support frame and a support member, such as a steel support channel, fastened on the top of the combine. The load cells produce analog data signals representative of weight of the collection basket at any given instance as the crop is harvested. The load cells transmit data analog signals to a data acquisition system (DAS) via a summing device and anti-aliasing filter. The DAS includes a CPU and an analog to digital converter to convert the analog load cell data to digital signals and digitally filters the digital signal to reduce signal noise resulting from harmonic vibrations of the combine straw walker mechanism for further processing. The CPU is interfaced with a global positioning device that provides time, latitude and longitude information of the combine to the CPU and also with a sensor that inputs tractor/combine information to the CPU from which combine speed can be determined. An interface device is provided on the tractor and interfaces to the CPU for providing signals representative of the number of rows harvested (row counter) to the CPU as input by the tractor operator. The CPU includes software for determining the instantaneous crop yield, yield rate, and area harvested as a crop field is being harvested for display to the tractor operator.

Continuous data seismic system

Abstract: A system for seismic data acquisition has been invented having, in certain aspects, one or multiple distributed data acquisition subsystems that are independent of energy source controller and/or of navigation system operation. Thus the distributed acquisition system(s) do not require a complicated and burdensome interface to the energy source controller or navigation systems. The seismic data acquisition system supplies a continuous flow of data which is buffered within a centralized data repository for short term storage until required by non-real-time processes. A seismic data acquisition method has been invented that replaces conventional closely coupled interaction between seismic acquisition systems and the energy source controller and the navigation systems by utilizing GPS time stamps on both the data as well as cycling events of the energy source controller and/or navigation systems to insure precise association of seismic data with cycling events. By continuously acquiring data with no interruption in the acquired data flow, association with energy source or navigation events may be accomplished at a latter point in time and not in the real-time operation of the acquisition subsystem.

Fuzzy logic enhanced digital PIV processing software

Abstract: Digital Particle image Velocimetry (DPIV) is an instantaneous, planar velocity measurement technique that is ideally suited for studying transient flow phenomena in high speed turbomachinery. DPIV is being actively used at the NASA Glenn Research Center to study both stable and unstable operating conditions in a high speed centrifugal compressor. Commercial PIV systems are readily available which provide near real time feedback of the PIV image data quality. These commercial systems are well designed to facilitate the expedient acquisition of PIV image data. However, as with any general purpose system, these commercial PIV systems do not meet all of the data processing needs required for PIV image data reduction in our compressor research program. An in-house PIV PROCessing (PIVPROC) code has been developed for reducing PIV data. The PIVPROC software incorporates fuzzy logic data validation for maximum information recovery from PIV image data. PIVPROC enables combined cross-correlation/particle tracking wherein the highest possible spatial resolution velocity measurements are obtained.

Vehicle data acquisition and display assembly

Abstract: A vehicle data acquisition and display assembly 10 which includes several cameras 75 which selectively and cooperatively receive images 77 from the environment or the ambient environment 83 in which a vehicle 60 resides. The acquired images 77 form a panoramic mosaic 85 , at least a portion of which is selectively displayed by a display assembly 45 within the vehicle 60.

Method and apparatus for extraction of nonlinear black-box behavioral models from embeddings of the time-domain measurements

Abstract: A method and apparatus that utilize time-domain measurements of a nonlinear device produce or extract a behavioral model from embeddings of these measurements. The method of producing a behavioral model comprises applying an input signal to the nonlinear device, sampling the input signal to produce input data, measuring a response of the device to produce output data, creating an embedded data set, fitting a function to the embedded data set, and verifying the fitted function. The apparatus comprises a signal generator that produces an input signal that is applied to the nonlinear device, the device producing an output signal in response. The apparatus further comprises a data acquisition system that samples and digitizes the input and output signals and a signal processing computer that produces an embedded data set from the digitized signals, fits a function to the embedded data set, and verifies the fitted function.

Using Continous Planning Techniques to Coordinate Multiple Rovers

Abstract: This paper describes a dynamic planning system for coordinating multiple rovers in collecting planetary surface data.

A module for energy and pulse shape data acquisition

Abstract: This paper describes a 4-channel data acquisition module designed for use with multi-electrode semiconductor detectors of X-ray and γ-rays. It combines high-speed waveform sampling with digital filtering to acquire accurate energy spectra at high rates and, at the same time, capture and store precisely measured waveforms.

Advanced radiation imaging of low-intensity gamma-ray sources

Abstract: Imaging gamma-ray sources and distributions of low intensity is difficult using current commercially available radiation imagers. Radiation Monitoring Devices, Inc. has carried out the research and development necessary to construct a novel, compact radiation-imaging device, RADCAM, for low-intensity applications. The device consists of a position-sensitive photomultiplier tube (PSPMT) coupled to a CsI(Na) scintillation crystal, which is an excellent candidate for such applications due to its high light output. A tungsten coded-aperture mask, placed in front of the scintillator, creates a gamma-ray intensity pattern across the face of the crystal. The PSPMT detects the resulting scintillation pattern and the analog output signals are captured and converted to digital signals by the RMD PSPMT interface card. The digital data is stored and processed by a portable personal computer. The gamma-ray “shadowgram” is then mathematically decoded to yield the original source image. The pseudo-color radiation-source image is overlaid on a video picture of the same area captured by a high-resolution CCD. The combined image is displayed on screen as an accurate map of radioactive gamma-ray sources in the physical environment. Data acquisition and image display are controlled by the IMager Acquisition and Graphical-user-interface Environment (IMAGE), a Windows-NT program developed for the imager.

Seismic data acquisition and method for spatially filtering seismic data

Abstract: A method of acquiring and processing seismic data involving deploying a number of seismic sensors, actuating a seismic source, receiving seismic signals produced by the seismic source using the seismic sensors, calculating offset distances (44) between the seismic source and the seismic sensors, and (42) producing spatially filtered seismic data from the received seismic signals. The inventive method may be used effectively with receiver arrays having smaller areal footprints and fewer sensors per receiver station location than conventional seismic data acquisition systems. It also allows ground roll and random noise to be effectively attenuated as the seismic data is spatially resampled or prepared for spatial resampling.