A Digitalization measurement method of large radius of curvature is presented in this paper. Non-contact Newton's rings are formed by an interferometer. The interferogram is imaged in ccd array. The scale of image...
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ISBN:
(纸本)0819439045
A Digitalization measurement method of large radius of curvature is presented in this paper. Non-contact Newton's rings are formed by an interferometer. The interferogram is imaged in ccd array. The scale of image pixels corresponding to Newton's rings that related to the radius of curvature is obtained by scanning fringes or other optical methods. The radius of curvature of spherical surface detected that can be both convex and concave is up to 25 Meter. The accuracy of measurement is better than 0.3 percent.
Holographic particle image velocimetry instruments at both velocity extremes have been developed and applied. Except for the type of laser required, the fundamental recording and data processing methods are similar fo...
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Holographic particle image velocimetry instruments at both velocity extremes have been developed and applied. Except for the type of laser required, the fundamental recording and data processing methods are similar for both cases. This paper summarizes recording and reconstruction schemes, software for data reduction, and methods for data presentation. An example application focuses on the extreme low-velocity case in which a three-size matrix of tracer particles was added to a solution in a crystal-growth-in-space experiment to quantify and analyse microconvection in a microgravity environment. Over 1000 holograms of 1000 particles were produced in a Spacelab mission, leading to the need to process millions of images. Particle velocities ranged from 0.1 to 1 mm h(-1). Reconstructed particle images were located with a computer traversed microscope imaged on a ccd array, and tracked with software designed to establish a reference frame in each hologram and precisely locate the particle centres. The measurements allow determination of the convective field, the residual gravitational field and gravity-jitter.
作者：
SMITH, JLVitro Techical Services
Simulation and Signatures Dept. Guided Weapons Evaluation Facility Eglin Air Force Base FL 32542
With the advent of focal plane arrays based on charge-coupled device (ccd) technology, confusion has arisen in the heretofore simple concept of modulation transfer function (MTF). The treatment of sampling phase varie...
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With the advent of focal plane arrays based on charge-coupled device (ccd) technology, confusion has arisen in the heretofore simple concept of modulation transfer function (MTF). The treatment of sampling phase varies, and factors are often omitted that should be included. It is proposed in this paper that MTF always represent a sample-phase-averaged value, and a list is offered for static MTF factors reflecting output waveform reconstruction from a ccd array.
Model of static Fourier spectrometer for atmosphere and ionosphere spectral investigation based on the Michelson interferometer with tilted mirrors and ccd detector is designed. Method of array sensor modulation trans...
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ISBN:
(纸本)0819426709
Model of static Fourier spectrometer for atmosphere and ionosphere spectral investigation based on the Michelson interferometer with tilted mirrors and ccd detector is designed. Method of array sensor modulation transfer function measurement is proposed. The ccd MTF and emission spectra of some light sources were obtained. Problems and results are discussed.
A prototype 32 x 32 array processor fabricated in 2-mu m charge coupled devices (ccd)/CMOS technology implementing the multiscale veto edge detection algorithm is presented, In this algorithm, differences between pixe...
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A prototype 32 x 32 array processor fabricated in 2-mu m charge coupled devices (ccd)/CMOS technology implementing the multiscale veto edge detection algorithm is presented, In this algorithm, differences between pixel values are computed in the original image, as well as after applying a series of smoothing filters of varying spatial scales, An edge exists between two pixels only if the magnitude of their difference is greater than a given threshold for all levels of smoothing tested, This algorithm maps particularly well to implementation as a focal plane processor as it requires only nearest neighbor communication, The ccd array performs the functions of image acquisition, charge loading and removal, and image smoothing, Analog circuits between each pair of pixels in the array compute the absolute value of difference between neighboring values and compare it to a global threshold, These circuits have been designed to allow reliable discrimination of differences from similar to 3.1% to similar to 10.1% of full scale range and thus meet the performance requirements of many machine vision applications.
A new approach is proposed for the on-line measurement of the maximum peak-to-valley roughness, R(max), of a finished-turned surface in the feed direction. The method is based on solving the inverse problem of light s...
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A new approach is proposed for the on-line measurement of the maximum peak-to-valley roughness, R(max), of a finished-turned surface in the feed direction. The method is based on solving the inverse problem of light scattering by using a linear least-square estimate of the angular scattered light pattern reflected from a surface. A laser system has been developed to capture the light reflected under different cutting conditions. The effects of the ambient room light as well as the workpiece's rotational speed and methods for thier compensation are also discussed. Good correlation was found between the optical and stylus-measured R(max).
Spatial maps of individual argon atomic emissions are measured in the GEC (gaseous electronic conference) reference reactor by monochromatic imaging, The plasma discharge is viewed through a grating monochromator, and...
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Spatial maps of individual argon atomic emissions are measured in the GEC (gaseous electronic conference) reference reactor by monochromatic imaging, The plasma discharge is viewed through a grating monochromator, and the images are recorded with an intensified charge-coupled device (ccd) array detector. Each atomic emission has a unique spatial profile that is related to the spatial energy distribution in the plasma.
When a ccd array is used to detect the spatial fringes of optical interference, interesting features emerge in the output as the width of each fringe approaches the dimension of a ccd sensing cell. These features are ...
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When a ccd array is used to detect the spatial fringes of optical interference, interesting features emerge in the output as the width of each fringe approaches the dimension of a ccd sensing cell. These features are theoretically studied and their application to the enhancement of the dynamic operating range of electrically scanned white-light interferometry is investigated. Preliminary experimental results are presented.
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