摘要:

AbstractA Fourier‐transforming coded aperture can be synthesized with a pair of two‐dimensional detector arrays, each preceded by a properly designed sequence of two Gabor‐zone plates. The coded image falling on one of the arrays corresponds to the cosine transform of the object. The coded image falling on the other array corresponds to the sine transform. Thus the Fourier transform of the object can be formed by using the first coded image as the real part, and the second coded image as the imaginary part, of the Fourier transform. Fourier‐transforming coded apertures of this type are capable of producing better resolution than spatial‐domain apertures. Although the system described in this article is specifically applied to a gamma‐ray camera, such a system is generally applicable to a wide varioty of noncoherent imagers.©1993 John W

ISSN:0899-9457    

DOI:10.1002/ima.1850040302

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractRadar systems combining coherent signals with frequency and angular diversity offer the possibility of synthesizing images of complex objects with spatial resolution of a few wavelengths. The availability of high‐quality microwave sources and components, high‐speed digital computers, and efficient signal‐processing algorithms allows radar imaging to be implemented in laboratory environments using commercially‐available equipment. The paper summarizes fundamental issues by addressing conceptual and practical limits of radar imaging and presents examples obtained from results of measurements in a laboratory environment. Implementation details of sophisticated operational imaging radars are not covered.©1993 John Wiley

ISSN:0899-9457    

DOI:10.1002/ima.1850040303

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe present a microwave pulse‐echo radar imaging technique and its application to nondestructive evaluation of structural configurations of the New York State Capitol building. The survey procedure consists of scanning surface areas of the building with the radar data acquisition system, imaging with the backward‐propagation method, and forming an image of the investigated region. This technique not only provides depth and other distance measures, but also provides high‐resolution range and azimuthal spatial visualization of the subsurface region. The results demonstrate the capability of the technique for estimating the depth, span, and size of beams, girders, flues, and masonry arches in floors as well as columns in walls. Also, the mechanical stepping and thickness of outer granite facings on the walls, and the presence of wire mesh and reinforcement in concrete, are also discernible.©1993 John Wiley&S

ISSN:0899-9457    

DOI:10.1002/ima.1850040304

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractA key source of digital images is the electro‐optical imaging sensor. The basic characteristic that identifies a digital electro‐optical sensor is conversion of reflected or emitted light from a scene or object into a digital image signal. Examples include television cameras with digital output, and scanning or staring cameras with digital output. We describe general system design techniques to derive optimum imaging sensor specifications, and we offer examples for two applications. One example application is for terrestrial thermal imaging of nearby objects, such as vehicles. The other example is a sensor to create a color image of small targets in low‐light, such as an automobile license plate from a distance of several meters.©1993 John Wiley&S

ISSN:0899-9457    

DOI:10.1002/ima.1850040305

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe matrix pencil (MP) method, based on the singular value decomposition (SVD), is applied to quantitative NMR spectroscopy. Its relationship to other SVD‐based methods is also presented. Simulations and applications are given to demonstrate the capability of superior performance.©1993 John Wiley&Sons

ISSN:0899-9457    

DOI:10.1002/ima.1850040306

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe analyze and demonstrate a scanning optical microscope that uses a vibrating knife‐edge corner to provide arbitrary, electronically variable resolution. Implications for general near‐field microscopy are discussed.©1993 John Wiley&Son

ISSN:0899-9457    

DOI:10.1002/ima.1850040307

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe describe a curvature‐based approach for estimating nonrigid motion of moving surfaces. We deal with conformal motion, which can be characterized by stretching of the surface. At each point, this stretching is equal in all directions but different for different points. The stretching function can be defined as additional (with global translation and rotation) motion parameter. We present a new algorithm for local stretching recovery from Gaussian curvature, based on polynomial (linear and quadratic) approximations of the stretching function. It requires point correspondences between time frames but not the complete knowledge of nonrigid transformation. Experiments on simulated and real data are performed to illustrate performance and accuracy of derived algorithms. Noise sensitivity of the algorithm is also evaluated using Gaussian noise on simulated data.©1993 John Wiley&Sons

ISSN:0899-9457    

DOI:10.1002/ima.1850040308

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

ISSN:0899-9457    

DOI:10.1002/ima.1850040309

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

ISSN:0899-9457    

DOI:10.1002/ima.1850040310

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

ISSN:0899-9457    

DOI:10.1002/ima.1850040301

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY