Aperture Synthesis

Methods and Applications to Optical Astronomy

Author: Swapan Kumar Saha

Publisher: Springer Science & Business Media

ISBN: 9781441957108

Category: Science

Page: 466

View: 5521


This book deals with the fundamentals of stellar interferometry with emphasis on aperture synthesis using sparse array of telescopes particularly at optical/IR wavelengths, the origin, properties, and optical effects of turbulence in the Earth's atmosphere, techniques developed to overcome image degradation. Studded with more than one hundred and fifty illustrations and tens of footnotes, it addresses the basic tricks of trade, current trend, motivation, methods, and path to future promise of true interferometry both from the ground and space. Also discussed are the technical challenge involved, such as beam transportation and recombination, detecting fringes using modern sensors, and image synthesis. Astronomical science that benefits from aperture synthesis imaging are highlighted as well.

Self-Organized Surface Structures with Ultrafast White-Light

First Investigation of LIPSS with Supercontinuum

Author: Sebastian Uhlig

Publisher: Springer

ISBN: 3658098945

Category: Science

Page: 97

View: 9177


Sebastian Uhlig presents the first experimental investigation of self-organized surface structures (LIPSS) generated by ablation from different (semiconductor and metallic) targets with an ultrafast white-light continuum (WLC) spreading in wavelength from 400-750 nm. The main goal is to study the possibility of LIPSS formation upon irradiation with an incoherent and polychromatic light source (e.g. the WLC) in order to discriminate between the two debated formation scenarios. The generation of a suitable WLC in terms of sufficient white-light pulse energy, broad spectral bandwidth, and low spatial coherence for the LIPSS generation, as well as the characterization of this WLC are additional important objectives of this work.

An Introduction to Radio Astronomy

Author: Bernard F. Burke,Francis Graham-Smith

Publisher: Cambridge University Press

ISBN: 052187808X

Category: Science

Page: 444

View: 3401


This well-established, graduate-level textbook is a thorough introduction to radio telescopes and techniques for students and researchers new to the subject.

Optical and Digital Image Processing

Fundamentals and Applications

Author: Gabriel Cristobal,Peter Schelkens,Hugo Thienpont

Publisher: John Wiley & Sons

ISBN: 3527635254

Category: Technology & Engineering

Page: 988

View: 8642


In recent years, Moore's law has fostered the steady growth of the field of digital image processing, though the computational complexity remains a problem for most of the digital image processing applications. In parallel, the research domain of optical image processing has matured, potentially bypassing the problems digital approaches were suffering and bringing new applications. The advancement of technology calls for applications and knowledge at the intersection of both areas but there is a clear knowledge gap between the digital signal processing and the optical processing communities. This book covers the fundamental basis of the optical and image processing techniques by integrating contributions from both optical and digital research communities to solve current application bottlenecks, and give rise to new applications and solutions. Besides focusing on joint research, it also aims at disseminating the knowledge existing in both domains. Applications covered include image restoration, medical imaging, surveillance, holography, etc... "a very good book that deserves to be on the bookshelf of a serious student or scientist working in these areas." Source: Optics and Photonics News

High Resolution Imaging

Detectors and Applications

Author: Swapan K. Saha

Publisher: CRC Press

ISBN: 9814613282

Category: Science

Page: 600

View: 6142


Interferometric observations need snapshots of very high time resolution of the order of (i) frame integration of about 100 Hz or (ii) photon-recording rates of several megahertz (MHz). Detectors play a key role in astronomical observations, and since the explanation of the photoelectric effect by Albert Einstein, the technology has evolved rather fast. The present-day technology has made it possible to develop large-format complementary metal oxide–semiconductor (CMOS) and charge-coupled device (CCD) array mosaics, orthogonal transfer CCDs, electron-multiplication CCDs, electron-avalanche photodiode arrays, and quantum-well infrared (IR) photon detectors. The requirements to develop artifact-free photon shot noise-limited images are higher sensitivity and quantum efficiency, reduced noise that includes dark current, read-out and amplifier noise, smaller point-spread functions, and higher spectral bandwidth. This book aims to address such systems, technologies and design, evaluation and calibration, control electronics, scientific applications, and results. One of the fastest growing applications is signal sensing, especially wavefront sensing for adaptive optics and fringe tracking for interferometry, which is important for long-baseline optical interferometry. The coherence time of the atmosphere is a highly variable parameter. Depending upon the high velocity wind, it varies from This book deals with the fundamentals of the important aspects of high-resolution imaging, such as electromagnetic radiations, particularly, optical wavelengths and their distortions due to optical elements and Earth’s atmosphere while passing through a detector; semiconductor physics; lasers; fiber optics; photon-detection process; photodetectors; charge-transfer devices; photon-counting devices in visible wavelength; radiation detectors in infrared wavelengths; and detecting systems for high energies.

The Paraboloidal Reflector Antenna in Radio Astronomy and Communication

Theory and Practice

Author: Jacob W. M. Baars

Publisher: Springer Science & Business Media

ISBN: 0387697349

Category: Science

Page: 253

View: 1925


Radio astronomers have developed techniques of calibration of large reflector antennas with radio astronomical methods, but these have not been comprehensively described. This text aims to fill this gap, taking a practical approach to the characterisation of antennas. All calculations and results in the form of tables and figures have been made with Mathematica by Wolfram Research. The reader can use the procedures for the implementation of his own input data.

Info Source

Sources of federal government information

Author: Canada

Publisher: N.A


Category: Administrative agencies

Page: N.A

View: 1130