The primary inducement for organizing an international Conference on 'Image Processing Techniques in_Astronomy' was the fact that the recording microdensitometer VAMP ('Vol Automatische Micro Photometer') of the Utrecht Astronomical Institute was operative for a few years. The necessity of comparing the in strument and its performance with similar instruments nowadays available at many other institutes, was stimulating enough to organize a meeting on the above subject. It took place in Utrecht on March 25, 26 and 27, 1975. The Scientific Organizing Committee consisted of J. Borgman (Groningen), R.B. Dunn (Sacramento Peak), H. Elsasser (Heidelberg), L.D. de Feiter, T. de Groot, J.R.W. Heintze, C. de Jager, H. Nieuwenhuijzen (Utrecht) and W. Wiskott (Geneve). About 175 scientists from 14 countries participated in the meeting which appeared to be successful and offered a good opportunity of exchanging information and comparing experiences. The VAMP was bought with financial support of the Utrecht University and the Netherlands Foundation for Scientific Research (Z.W.O.). The conference was organized with financial support from The Netherlands Ministry of Science and Education, The European Southern Observatory, The Leids Kerkhoven-Bosscha Fonds, The Astronomical Institute of Utrecht, to which Institutes and Organisations we express our sincere gratitude. C. de Jager H. Nieuwenhuijzen editors PAR T WHAT INFORMATION DO WE NEED, FOR WHICH ASTRONOMICAL PROBLEM? ASTROMETRY K. Aa. Strand U. S. Naval Observatory Washington, D. C, INTRODUCTION Considerable progress has taken place in astrometry over the past two decades.

Inhalt
1 What Information Do We Need, for Which Astronomical Problem?.- Astrometry.- Photometry.- The Photometry of Extended Objects: Diode Array Detectors and Interactive Data Processing.- Trends in Astronomical Spectroscopy.- 2 Acquisition and Storage.- Information Retrieval by Microdensitome Try.- Fourier Techniques.- Television Detector Techniques.- On Line Digital Correlation of Photon Counting TV Images for Stellar Interferometry.- Photon-Counting Detector Arrays Based on Microchannel Array Plates.- Performance of the MIT Silicon Vidicon Imaging System at the Telescope.- A Self-Scanned Silicon Diode Array for Astronomical Photometry.- Image Detectors for Recording Astronomical Ultraviolet Spectra.- Mesure Des Contours de Raies par les Techniques de Television.- Photometry using Electronographic Techniques.- Integrating TV System Development at Cambridge.- Sec Vidicon System for a Balloon Ultraviolet Stellar Spectrometer.- Problems of Oversampling with Sec Vidicon Television Systems.- Some Experiments with an Sec Image Tube for High Precision Multi-Colour Photometry of Galactic Clusters.- 3 Processing Hardware.- Four Years Experience in APMS Star Plate Processing Results and Future Plans.- The Use of the Galaxy Machine at the Royal Greenwich Observatory.- The Fully Automatic Program-Controlled Microdensitometer-Comparator of the Astronomical Institute at Utrecht.- The Grant Measuring Engine.- The U.S. Naval Observatory's Automatic Measuring Machines.- The Two-Coordinate Grant Machine in Long-Focus Astrometry.- The Cosmos Facility at the Royal Observatory Edinburgh.- The ESO S-3000 Measuring Machine.- Iris A Two Axis Comparator and Microdensitometer using Two Different Scanning Modes.- Machine a Mesurer de L'Observatoire de Haute Provence.- The Design ofthe New S.R.C. Automated Photographic Measuring System.- The Computer Controlled Comparator Astroscan.- A Simultaneous Six-Channel Microphotometer with Computerized Data Acquisition.- A Very Simple Digital Microdensitometer-Comparator.- Photoelectric Spectroscopic Plate Measuring Machine Built at the Meudon Observatory.- 4 Software Techniques.- Software Techniques for Image Processing.- Problems of Machine Independency and Interactive Matters.- Aperture Synthesis.- Interactive Computer Reduction and Display of Radio Super-Synthesis Maps.- The Design of Vamp Software for the Measurement and Reduction of Stellar Spectrograms.- Development of Digital System for Stellar Spectra Reduction at Toru? Observatory.- Evaluation of Master Scans of Photographic Stellar Images.- Image Processing Systems Developed at MIT to Handle Silicon Vidicon Images and Spectra of Astronomical Objects.- Handling of 'Galaxy' Photometry.- 5 Applications to Astronomical Problems.- Some Preliminary Results Obtained with a TV Camera in the Field of the Observation of Visual Double Stars.- Echelle Spectra Image Processing for the International Ultraviolet Explorer.- Semi-Automatic Determination of Equivalent Widths.- Accuracy and Results of Spectrophotometry with Objective Prism Plates.- Le Centre de Depouillement de Cliches Astronomiques.- Intercomparison of Ground Based and Satellite Pictures of the Sun.- Flying-Spot Analysis of Solar Images.- Removal of Vignetting from Apollo Low Light Level Photographs.- Search of Significant Features in a Direct non Parametric Pattern Recognition Method. Application to the Classification of a Multiwire Spark Chamber Pictures.- Lock-In Image Subtraction Detectability of Circumstellar Planets with the Large Space Telescope.- Digital Image Centering, I..