Image Formation From Coherence Functions in Astronomy : Proceedings of IAU Colloquium No. 49 on the Formation of Images From Spatial Coherence Functions in Astronomy, Held at Groningen, The Netherlands, 10–12 August 1978

The IAU Colloquium No.49, on the formation of images from spatial coherence functions in astronomy, was held at Groningen, the Netherlands, during the period 10-12 August 1978. The colloquium was attended by 108 participants from 14 countries (U.S.A. 29, the Netherlands 20, U.K. 19, Germany 10, France 7, Australia 5, Canada 5, Japan 4, India 2, New Zea­ land 2, Sweden 2, Argentina I, Belgium I, Israel I). It was sponsored by the Netherlands Foundation for Radio Astronomy, the International Astronomical Union, the Department of Education and Sciences, the Union Radio-Scientifique Internationale, the Leiden Kerkhoven-Bosscha Foundat­ ion and the State University at Groningen. This volume contains 36 of the 37 papers presented. Nearly all papers are followed by a sununary of the discussion that took place after their presentation. A few papers, published in full elsewhere, are given only as abstracts. The majority of the papers are related to aperture synthesis in radio astronomy; a small number deal with optical astronomy and with applications in acoustics and medicine. The presentations are divided in 7 groups: aperture synthesis and its deficiencies, the problem of limited or missing phase information, techniques for processing and data display, optical interferometric methods, maximum entropy image reconstruction, other image improvement methods, and a survey of image formation from projections. Each group contains one or two invited lectures (see Table of Contents), intended as surveys of particular areas; on the average they occupy twice as many pages as the other papers. Front Matter....Pages i-xi Front Matter....Pages 1-1 Fundamentals and Deficiencies of Aperture Synthesis....Pages 3-18 The Two Dimensional Representation Of Three Dimensional Interferometer Measurements....Pages 19-26 Measurement Errors in Rotational Synthesis and their Effects in the Map Plane....Pages 27-45 “Kneading”: The Adjustment of Instrumental Phase and Gain Parameters to Suppress Error Patterns in a Synthesis Map....Pages 47-53 A Proposal to Obtain Short Spacing Information by Interpolation....Pages 55-58 The Short Spacings Problem in Correlation Interferometers and a Procedure for Solving It....Pages 59-59 Short Spacing Synthesis from a Primary Beam Scanned Interferometer....Pages 61-63 Front Matter....Pages 65-65 Fundamental Aspects of Aperture Synthesis with Limited or No Phase Information....Pages 67-82 Map Making with Non-Phase Stable Interferometers....Pages 83-91 Image Reconstruction from VLBI Amplitude and Phase Closure Data....Pages 93-93 On the Danger of Applying Statistical Reconstruction Methods in the Case of Missing Phase Information....Pages 95-101 Reduction of Phase Noise in Interferometry with State-Space Analysis....Pages 103-110 Front Matter....Pages 111-111 Digital Processing Methods for Aperture Synthesis Observations....Pages 113-120 Digital Hardware Processing of Rotational Synthesis Data....Pages 121-121 Analogue Processing Methods for Synthesis Observations....Pages 123-141 Exploring Methods of Effective Data Display in an Interactive Astronomical Data-Processing Environment....Pages 143-155 Processing and Display of Spectral Line Absorption Maps....Pages 157-157 A Proposed Correlator Back-End ror the Culgoora Radioheliograph....Pages 159-164 An Acousto-Optical Image Processor and its Application to a 160 Mhz Interferometer....Pages 165-172 Front Matter....Pages 173-173 Imaging with a Coherence Interferometer in Optical Astronomy....Pages 175-185 Front Matter....Pages 173-173 Towards Imaging of Star Clusters by Speckle Interferometry....Pages 187-193 Front Matter....Pages 195-195 Resolution Enhancement; the “Maximum Entropy Method” and the “High Resolution Method”....Pages 197-218 The Maximum Entropy Method....Pages 219-225 The Use of Bayesian Statistics in Image Estimation from Interferometer Data....Pages 227-234 Problems with Maximum Entropy....Pages 235-235 The Introduction of a Priori Knowledge in Certain Processing Algorithms....Pages 237-239 Extending the Fourier Transform — The Positivity Constraint....Pages 241-247 The Information of Images and its Dependence on Noise and Spatial Resolution....Pages 249-255 Maximum Entropy Spectral Analysis — Some Comments....Pages 257-257 Front Matter....Pages 259-259 The Method ‘Clean’ — Use, Misuse and Variations....Pages 261-275 Fitting a Gaussian Model to Aperture Synthesis Data by Akaike’s Information Criterion (AIC)....Pages 277-286 An Optimum Deconvolution Method....Pages 287-290 Application of the Simplex Algorithm to Image Restoration....Pages 291-291 Observations of Extended Radio Sources using a Multiple-Beam Technique....Pages 293-298 Formation of Acoustic Images from Spatial Coherence Functions: Processing by Superresulotion Techniques....Pages 299-313 Front Matter....Pages 315-315 Reconstruction from Projections in Medicine and Astronomy....Pages 317-325 Back Matter....Pages 327-337 The IAU Colloquium No. 49, on the formation of images from spatial coherence functions in astronomy, was held at Groningen, the Netherlands, during the period 10-12 August 1978. The colloquium was attended by 108 participants from 14 countries (U.S.A. 29, the Netherlands 20, U.K. 19, Germany 10, France 7, Australia 5, Canada 5, Japan 4, India 2, New ZeaƯ land 2, Sweden 2, Argentina I, Belgium I, Israel I). It was sponsored by the Netherlands Foundation for Radio Astronomy, the International Astronomical Union, the Department of Education and Sciences, the Union Radio-Scientifique Internationale, the Leiden Kerkhoven-Bosscha FoundatƯ ion and the State University at Groningen. This volume contains 36 of the 37 papers presented. Nearly all papers are followed by a sununary of the discussion that took place after their presentation. A few papers, published in full elsewhere, are given only as abstracts. The majority of the papers are related to aperture synthesis in radio astronomy; a small number deal with optical astronomy and with applications in acoustics and medicine. The presentations are divided in 7 groups: aperture synthesis and its deficiencies, the problem of limited or missing phase information, techniques for processing and data display, optical interferometric methods, maximum entropy image reconstruction, other image improvement methods, and a survey of image formation from projections. Each group contains one or two invited lectures (see Table of Contents), intended as surveys of particular areas; on the average they occupy twice as many pages as the other papers