Self-similarity in Walsh Functions and in the Farfield Diffraction Patterns of Radial Walsh Filters
Self-similarity in Walsh Functions and in the Farfield Diffraction Patterns of Radial Walsh Filters

Author: Lakshminarayan Hazra

Publisher: Springer

Published: 2017-06-09

Total Pages: 89

ISBN-13: 9811028095

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The book explains the classification of a set of Walsh functions into distinct self-similar groups and subgroups, where the members of each subgroup possess distinct self-similar structures. The observations on self-similarity presented provide valuable clues to tackling the inverse problem of synthesis of phase filters. Self-similarity is observed in the far-field diffraction patterns of the corresponding self-similar filters. Walsh functions form a closed set of orthogonal functions over a prespecified interval, each function taking merely one constant value (either +1 or −1) in each of a finite number of subintervals into which the entire interval is divided. The order of a Walsh function is equal to the number of zero crossings within the interval. Walsh functions are extensively used in communication theory and microwave engineering, as well as in the field of digital signal processing. Walsh filters, derived from the Walsh functions, have opened up new vistas. They take on values, either 0 or π phase, corresponding to +1 or -1 of the Walsh function value.

Azimuthal Walsh Filters
Azimuthal Walsh Filters

Author: Indrani Bhattacharya

Publisher: Springer Nature

Published: 2020-08-13

Total Pages: 123

ISBN-13: 9811560994

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This book explores the possibility of using azimuthal Walsh filters as an effective tool for manipulating far-field diffraction characteristics near the focal plane of rotationally symmetric imaging systems. It discusses the generation and synthesis of azimuthal Walsh filters, and explores the inherent self-similarity presented in various orders of these filters, classifying them into self-similar groups and sub-groups. Further, it demonstrates that azimuthal Walsh filters possess a unique rotational self-similarity exhibited among adjacent orders. Serving as an atlas of diffraction phenomena with pupil functions represented by azimuthal Walsh filters of different orders, this book describes how orthogonality and self-similarity of these filters could be harnessed to sculpture 2D and 3D light distributions near the focus.

Optics News
Optics News

Author:

Publisher:

Published: 1986

Total Pages: 1144

ISBN-13:

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Includes a directory of members in one issue each year.

Azimuthal Walsh Filters
Azimuthal Walsh Filters

Author: Indrani Bhattacharya

Publisher: Springer

Published: 2020-11-02

Total Pages: 114

ISBN-13: 9789811560989

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This book explores the possibility of using azimuthal Walsh filters as an effective tool for manipulating far-field diffraction characteristics near the focal plane of rotationally symmetric imaging systems. It discusses the generation and synthesis of azimuthal Walsh filters, and explores the inherent self-similarity presented in various orders of these filters, classifying them into self-similar groups and sub-groups. Further, it demonstrates that azimuthal Walsh filters possess a unique rotational self-similarity exhibited among adjacent orders. Serving as an atlas of diffraction phenomena with pupil functions represented by azimuthal Walsh filters of different orders, this book describes how orthogonality and self-similarity of these filters could be harnessed to sculpture 2D and 3D light distributions near the focus.

Interferometry and Synthesis in Radio Astronomy
Interferometry and Synthesis in Radio Astronomy

Author: A. Richard Thompson

Publisher: Wiley-Interscience

Published: 1986-04-28

Total Pages: 568

ISBN-13:

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A unified description of the theory and practice of radio interferometry and synthesis mapping techniques as they apply to astronomy and geology. Beginning with an historical review, it goes on to provide a detailed description of all aspects of radio inferometry, from basic principles through instrumental design to data reduction. Over 450 original papers and monographs are cited.

High Resolution Imaging in Microscopy and Ophthalmology
High Resolution Imaging in Microscopy and Ophthalmology

Author: Josef F. Bille

Publisher: Springer

Published: 2019-08-13

Total Pages: 411

ISBN-13: 3030166384

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This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.

Ambisonics
Ambisonics

Author: Franz Zotter

Publisher: Springer

Published: 2019-04-30

Total Pages: 223

ISBN-13: 3030172074

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This open access book provides a concise explanation of the fundamentals and background of the surround sound recording and playback technology Ambisonics. It equips readers with the psychoacoustical, signal processing, acoustical, and mathematical knowledge needed to understand the inner workings of modern processing utilities, special equipment for recording, manipulation, and reproduction in the higher-order Ambisonic format. The book comes with various practical examples based on free software tools and open scientific data for reproducible research. The book’s introductory section offers a perspective on Ambisonics spanning from the origins of coincident recordings in the 1930s to the Ambisonic concepts of the 1970s, as well as classical ways of applying Ambisonics in first-order coincident sound scene recording and reproduction that have been practiced since the 1980s. As, from time to time, the underlying mathematics become quite involved, but should be comprehensive without sacrificing readability, the book includes an extensive mathematical appendix. The book offers readers a deeper understanding of Ambisonic technologies, and will especially benefit scientists, audio-system and audio-recording engineers. In the advanced sections of the book, fundamentals and modern techniques as higher-order Ambisonic decoding, 3D audio effects, and higher-order recording are explained. Those techniques are shown to be suitable to supply audience areas ranging from studio-sized to hundreds of listeners, or headphone-based playback, regardless whether it is live, interactive, or studio-produced 3D audio material.