bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lightning Locators
Authors: Shirer Hampton N. , Roeder William P. , Shirer Hampton W. , D'Arcangelo David L. , Hilliker Joby , Koval Joe , Magee Nathan , Mazeroski David W. 
Published: October 2003

AbstractLocating lightning in real time is an old problem. Radio techniques developed in the early to mid‐twentieth century used crossed‐loopcathode‐ray direction finders(CRDF) that provide the bearing but not the range to the lightning source.Direction‐finding(DF) systems typically sense the radio signal, known asatmospherics,spherics, or ‘sferics, that is emitted by lightning and that most listeners of AM radios interpret as interference,static, orradio noise. Quite generally, lightning radiates electromagnetic pulses that span an enormous range of frequencies. In this article, theradio signalrefers to the portion of the electromagnetic spectrum that covers frequencies less than 3 × 108kilohertz (denoted kHz), or 300 GHz, and the optical signal refers to frequencies greater than 3 × 108kHz. Also, when not qualified here, electromagnetic radiation refers to the radio signal.Lightning sensing systems have important applications in meteorology. Certainly, these systems can help to detect and forecast the arrival of thunderstorms by monitoring their positions, motions, and intensities. Such systems are also important for lightning safety and for protecting natural resources in a diverse set of real‐time applications, including fire and personnel safety, aircraft routing, missile launch decisions, power grid operation, and weather forecasting. Lightning is a significant threat to people but far too often is underrated. Lightning sensing systems, especially those that detect intracloud lightning, are being investigated as tools for predicting severe thunderstorms, including tornadoes, microbursts, and hail. Lightning data are also being investigated as possible input for small‐scale numerical weather forecast models to supplement the usual observations of pressure, temperature, humidity, and winds.This article is not an exhaustive survey of all real‐time and research lightning location systems, but it provides a comprehensive overview of the topic. It is split into two major parts; the first reviews the many important concepts and defines the terminology used to describe them, and the second covers the different major types of operational lightning location systems by describing an example of each in detail.Many of the lightning facts herein are documented thoroughly in the references. The methods and detection systems reviewed in this article are also described on various World Wide Web (www) sites. The addresses for many of these sites are given.
Liquid Crystal Display Technology
Authors: Crawford Gregory P. , Escuti Michael J. 
Published: October 2003

AbstractAs the display in most imaging systems is the final medium through which an image is rendered for manipulation and verification, an understanding of display technologies is essential to the imaging process. Because individuals working in the field of imaging science and technology may spend more time looking at a display screen than at anything else in their office or laboratory, it is imperative that it be comfortable to use and appropriate for the particular context.Twenty years ago, system manufacturers often integrated the electronic display directly into the system to provide a complete package for a specified imaging application. Although this approach does not afford much flexibility, the display could be closely matched to a specific application because user requirements were well defined. This custom design approach enabled optimizing the graphics controller, system software, and user interface for the display, user, and application requirements. Despite the positive attributes of this “black‐box” approach, such as high performance and superior application specific image quality, closed architecture platforms tend to be more expensive and suffer from incompatibility with peripheral add‐ons and software packages not supported by the system manufacturer.Today, the situation is dramatically different due to the continual evolution of the graphics controller interface. By mixing images with text and graphics, software developers require more from the display to support moving images without diminishing display performance for static images. The graphical capability of today's standard computer platforms has now made it unprofitable for vendors of imaging systems to develop their own displays for system‐specific tasks. End users now typically purchase a computer platform, display, and a variety of other peripherals from multiple vendors and integrate them with ease (i.e., a plug‐and‐play philosophy). In such a marketplace, one must be well educated to match display technology to application needs. This article provides the reader with a fundamental knowledge of working principles of liquid crystal displays (LCDs), their capabilities, and their limitations.
Magnetic Field Mapping
Authors: Henrichsen K. N. 
Published: October 2003

AbstractMagnetic field mapping is the production of maps or images of magnetic fields in space. Magnetic field maps are needed for designing and optimizing of magnets used in particle accelerators, spectrometers (mass, nuclear magnetic resonance, and electron paramagnetic resonance), and magnetic resonance imaging systems. Magnetic field maps are also used in geologic exploration where the variations in the magnitude and direction of the earth's magnetic field are indicative of subsurface features and objects. Field mapping relies on various methods of measuring the magnetic field, generally one point at a time. These measurement methods are the main focus of this article.It is curious to note that most measurement methods have remained virtually unchanged for a very long period, but the equipment has been subject to continual development. In this article, only the more commonly used methods are discussed. These methods are complementary and a wide variety of the equipment is readily available from industry. For the many other existing measurement methods, a more complete discussion can be found in two classical bibliographical reviews. Much of the material was presented at the CERN Accelerator School on Measurement and Alignment of Accelerator and Detector Magnets.
Foundations of Morphological Image Processing
Authors: Dougherty Edward R. 
Published: October 2003

AbstractThe basic morphological operations of erosion, dilation, opening, and closing are a part of every image processing toolbox. So too are many basic algorithms such as the watershed and top‐hat transforms. This article reviews the fundamental algebraic theory of mathematical morphology as applied to Euclidean set theory, the context in which it was originally conceived by Matheron and Serra from mathematical operations dating back to Minkowski and Hadwiger. Thorough knowledge of basic algebraic theory is required for anyone engaged in serious research in morphological image processing and is very beneficial for anyone interested in advanced applications.Since its original set‐theoretic formulation, mathematical morphology has been extended to real‐valued functions and to lattice‐valued functions. These extensions take note of the fact that the operations and propositions of the algebraic theory depend on order relations. This can be seen in the direct generalization of many binary definitions and properties to lattices based on the partial order relation among sets. In many cases, the definitions in this article are extended to lattices (including real‐valued and integral‐valued functions) by changing the subset relation ⊂ to the order relationship ≤.This article restricts attention to binary morphology.
Motion Picture Photography
Authors: Hope Thomas W. 
Published: October 2003

Abstract
It is not the intention of this article on motion picture photography to be all encompassing. Motion picture photography as a professional industry has many facets. In effect, this is a compendium. Subjects pertaining more closely to imaging are covered in greater detail than others not directly involving imaging. For definitions of many terms used here, consult the glossary. Motion picture photography, dating from the 1890s, is one of the oldest of modern imaging, technologies that remains current today.

Motion picture theory is simple and clear‐cut. Motion film is composed of a series of still pictures. When the still pictures are projected progressively and rapidly onto a screen, the eye perceives motion, hence they become a motion picture. This is termed
persistence of vision
. In a conventional sound motion picture, 24 individual pictures are projected onto the screen in one second. The screen is blank (black) for 1/96th second. While picture number one is blanked out, the film moves to picture number two. The eye and mind retain the image of picture number one for that fraction of a second when the screen is black. If, for example, something in motion is being photographed, the difference between image one and image two is minute. The eye and memory record a smooth transition from picture one to picture two. This is perceived as motion.

Oxygens of motion picture photography are discussed.

Photographic film used for motion pictures is normally a thin strip or ribbon. The exception is wide format films, 65 mm and 70 mm used for
wide‐screen
shows. Composition types and properties of film are detailed.

A motion picture camera is a lighttight precision instrument. All professional cameras, with a few exceptions, are operated by an electric motor. The power can be supplied by a battery in the field or ac power in the studio.
Essentially, there are two types of projectors. Both operate using the same basic configuration of picture head, optics, and shutter system. The major difference is in the film supply and take‐up system.
Particle Detector Technology for Imaging
Authors: Taylor Geoffrey N. 
Published: October 2003

AbstractIn this article, “particles” refer to charged particles that have enough energy to pass some significant distance through matter. The interaction of particles with matter forms the basis on which particle detectors are designed and operated. The principal process for detection is ionization of matter by the electromagnetic interaction of the moving particle. Ionization produces free charge that can be collected and detected. Electromagnetic radiation from the charged particle moving through matter may also be used to create a detectable signal. Neutral particles can be observed following their interaction with matter, producing one or several charged particles, that are subsequently detected.The development of particle detectors has occurred within the fields of nuclear and high‐energy particle physics. In this regime, the interest lies in reconstructing particles emanating from a particle interaction or from the decay of unstable particles or nuclei. The trajectories of the detected particles are recorded to reconstruct the kinematics (momentum and energy of the particles) of the reactions being observed. The particle trajectories are sampled as the particles pass through the detector elements. The sampled track positions are used to reconstruct the full trajectory.In addition to the kinematics of such reactions, spatial information is also important, especially when determining the distance that an unstable particle travels before decaying. The decay time distributions of unstable particles follow the exponential statistical time distributions of radioactive decays whose half‐lives or lifetimes are characteristic of the particle or the nuclear state being studied. For sufficiently long lifetimes, the combination of track length before decay and the reconstructed kinematics of the decay products are used to determine the decay time of individual decays. The ensemble of data is then used to extract the characteristic lifetime of the particle from the distribution of the individual decays.The most common particles that can be tracked and imaged include electrons, protons, some nuclei, muons, pions, kaons, and neutrinos. High‐energy photons (X rays and gamma rays) also have particlelike properties and provide great utility in imaging applications. The source of the particles can be radioactive tracers distributed within the object being imaged or an external source such as a radioactive source, a reactor, an accelerator, or cosmic rays.
Photodetectors
Authors: Wadsworth Mark 
Published: October 2003

Abstract
Photons impinging upon matter interact in a manner determined by the nature of the chemical bonds in the material and the energy of the incident photons. Interacting photons may be reflected, refracted, diffracted, transmitted, or absorbed. Each of these phenomena can be used to measure some parameter of interest in chemical analysis. Photo‐assisted chemical analytical techniques require an accurate, sensitive method of photon detection and quantification. Photographic film proved to be the first useful method for such evaluations. Later, photomultiplier tubes provided the means to improve many photo‐analytical techniques. With the advent of semiconductor technology, numerous single‐element, broad‐spectrum photodetecting devices were developed and applied to the task. Most recently, photodetector technology has entered the age of high density integration. Large‐area photon detectors are becoming commonplace in most analytical equipment. The advances afforded by these devices have allowed for significant improvements in the performance of systems designed for photo‐analytical chemical analysis in general, and specifically for spectroscopic‐based equipment. A working knowledge of the operation and limitations of photodetectors is therefore necessary for the modern chemist.
Photodetector devices convert electromagnetic radiation or photons to electric signals which can be processed to obtain the spectral, spatial, and temporal information inherent in the radiation. Photodetectors, may be operated in many modes. The more popular ones are photoconductors, photodiodes, charge‐transfer devices, and pyroelectrics. The detectors may be used as single elements such as in street light controls, film camera exposure control, or motion detectors for security. Photodetectors also find application in the form of linear arrays used in analytical spectrometers, night‐vision equipment, in small, low cost spectrometers for the control of building ventilation and environmental pollution monitoring or configured as large matrix arrays in video cameras. This chapter includes the following topics: Principles; figures of Merit; photodetector modes of operation; detector fabrication and performance; and health and safety factors.
RF
Magnetic Field Mapping
Authors: Hornak Joseph P. 
Published: October 2003

Abstract
Radio‐frequency (RF) magnetic field mapping is the imaging of oscillating magnetic fields in space. The title of this article implies RF mapping, however, the technique is applicable to both higher frequency microwaves and lower audio frequency electromagnetic waves.
Five mapping techniques are presented in this article. They were developed for mapping the oscillating magnetic fields (standing waves) associated with inductive–capacitive–resistive (LCR) circuits, such as cavity resonators and resonant coils used in magnetic resonance spectroscopy and imaging. LCR circuits store energy alternately in the capacitive element as electrical fields and in the inductive element as magnetic fields. The oscillating magnetic fields form a standing wave within the volume of the inductor. The electrical fields are either zero or separated in space from the magnetic fields, and hence generally are not detected in these circuits. This point is worth noting because some of the techniques presented in this article cannot distinguish oscillating magnetic and electrical fields.
Because of the magnetic resonance application of these techniques, much of the magnetic resonance symbolism has been adopted, and some basic magnetic resonance theory will be presented.

The mapping techniques are divided into two general categories: probe and imaging techniques. Probe techniques produce field values at discrete points in space that can be used to generate a
B
1
map. Imaging techniques produce an image directly. The method depends on the proportionality of the intensity of a pixel in this image to the magnetic field at the corresponding point in space.
Scanning Acoustic Microscopy
Authors: Tittmann Bernhard R. , Miyasaka Chiaki 
Published: October 2003

AbstractThis article is an overview of scanning acoustic microscopy, which is one of the more advanced ultrasonic imaging technologies. The scanning acoustic microscope (SAM) uses ultrasound to produce enlarged images of the microscopic structures of materials. In other words, the SAM is an instrument that subjects an object to ultrasound and detects the variations of the elastic properties of the object. The elastic properties are determined by the molecular arrangement of the material, molecule size, intermolecular force or the like, and each material has its unique characteristics. Accordingly, each object reacts in its own peculiar way when subjected to ultrasonic waves. The waves received from the object can be converted into an image. Because ultrasonic waves can penetrate into an object's interior, the surface and also the interior can be visualized.The contents of this article are as follows: First, the need in industry for this process is described. Second, the history of the development of the SAM is illustrated in brief. Third, the basic theory of ultrasonic imaging used in the SAM is depicted, as well as the basic theory of the implements used in the SAM. Furthermore, theV(z) curve method for material characterization is described. Selected images are given for a better understanding of the sections.
Silver Halide Detector Technology
Authors: Hailstone Richard 
Published: October 2003

AbstractThis article describes the basic construction and operation of silver halide materials as image recording devices. The detector consists of silver halide microscrystals coated in a gelatin–water mixture on either a transparent or paper support. Strictly speaking the resulting suspension of silver halide microcrystals in aqueous gelatin is classified as a dispersion but early on in the development of photography it was called an “emulsion.” Emulsion is used in this article. A latent image is formed via a photochemical change of the microcrystal. The visible image is created through an image processing step in which those microcrystals that have received sufficient light “blacken” as they are transformed from silver halide to metallic silver.The microcrystals, also called “grains,” are prepared in a variety of shapes and size distributions to accommodate a variety of applications. Over the range of applications, the microcrystal size varies from a few tenths of a micron diameter to several microns diameter. Sensitivity, or speed, increases with increasing grain size, so higher speed films must necessarily use larger grains. Materials intended for image capture need to produce a distinguishable output over a wide range of inputs arid so a polydisperse size distribution is used. On the other hand, materials for image display, such as prints, need to respond only over a relatively narrow range of inputs so a monodisperse size distribution is often used.
Single Photon Emission Computed Tomography (SPECT)
Authors: Madsen Mark T. 
Published: October 2003

AbstractSPECT (Single photon emission computed tomography) is a diagnostic imaging modality that produces tomographic slices of internally distributed radiopharmaceuticals. It is routinely used in the diagnosis of coronary artery disease and in tumor detection. Projection views of the radiopharmaceutical distribution are collected by one or more scintillation cameras mounted on a gantry designed to rotate about a patient lying horizontally on a pallet. The projection information is mathematically reconstructed to obtain the tomographic slices. Most clinical SPECT studies are qualitative with simplistic corrections for attenuation and scattered radiation. Quantitative SPECT requires corrections for attenuation, scatter and spatial resolution, although these have not been routinely implemented in the past because of their computational load. SPECT instrumentation has evolved to include coincidence imaging of positron emitting radiopharmaceuticals, specifically18F Fluorodeoxyglucose.SPECT imaging is expected to play a continuing important role in medical imaging. Future improvements in SPECT instrumentation are likely to include new detectors and collimation schemes. The primary motivating factor in SPECT imaging will continue to be the creation and implementation of new radiopharmaceuticals. SPECT use in tumor imaging will probably experience the largest growth. Applications will include treatment planning for internal radiation therapy as well as diagnostic studies.
Analog and Digital
SQUID
Sensors
Authors: Radparvar Masoud 
Published: October 2003

Abstract
Superconducting QUantum Interference Devices (SQUIDs) are extremely sensitive detectors of magnetic flux and can be used as low noise amplifiers for a variety of applications such as high resolution magnetometers, susceptometers, neuromagnetometers, motion detectors, ultrasensitive voltmeters, pico‐ammeters, readout of cryogenic detectors, and biomagnetic measurements. A SQUID is a superconducting ring interrupted by one or two Josephson tunnel junctions made of a superconductor such as niobium. Nb is the material of choice for superconducting circuits, because it has the highest critical temperature among the elemental superconductors (9.3 K). This alleviates certain uniformity and repeatability concern that must be taken into account when using compound superconductors. Josephson tunnel junctions using niobium as electrodes and thermally oxidized aluminum as tunnel barriers have been investigated rather extensively and have been brought to a state of maturity suitable for medium scale integrated circuits by several laboratories.

A typical SQUID circuit process uses 3–10 µm
2
area Josephson junctions with critical current density of 100–1000 A/cm
2
. These circuits are fabricated by a multilayer process with all niobium electrodes and wiring, aluminum oxide tunnel barrier, Mo or Au resistors, Au metallization, and SiO
2
insulating layers.