Library of Congress Preassigned Control Number Data

Keller, Christoph U.

Field guide to astronomical instrumentation / Christoph

Keller, Ramon Navarro, Bernhard Brandl.

pages cm. – (The field guide series ; FG32)

Includes bibliographical references and index.

ISBN 978-1-62841-177-5 (alk. paper)

1. Astronomical instruments–Handbooks, manuals, etc.

I. Navarro, Ramón

II. Brandl, Bernhard R.

III. Society of Photo-optical Instrumentation Engineers.

IV. Title.

QB86.K45 2014

522′.87–dc23

2014009876

Published by

SPIE

P.O. Box 10

Bellingham, Washington 98227-0010 USA

Phone: 360.676.3290

Fax: 360.647.1445

Email: Books@spie.org

www.spie.org

The content of this book reflects the thought of the author(s). Every effort has been made to publish reliable and accurate information herein, but the publisher is not responsible for the validity of the information or for any outcomes resulting from reliance thereon.

Printed in the United States of America.

First printing.

Introduction to the Series

Welcome to the SPIE Field Guides—a series of publications written directly for the practicing engineer or scientist. Many textbooks and professional reference books cover optical principles and techniques in depth. The aim of the SPIE Field Guides is to distill this information, providing readers with a handy desk or briefcase reference that provides basic, essential information about optical principles, techniques, or phenomena, including definitions and descriptions, key equations, illustrations, application examples, design considerations, and additional resources. A significant effort will be made to provide a consistent notation and style between volumes in the series.

Each SPIE Field Guide addresses a major field of optical science and technology. The concept of these Field Guides is a format-intensive presentation based on figures and equations supplemented by concise explanations. In most cases, this modular approach places a single topic on a page, and provides full coverage of that topic on that page. Highlights, insights, and rules of thumb are displayed in sidebars to the main text. The appendices at the end of each Field Guide provide additional information such as related material outside the main scope of the volume, key mathematical relationships, and alternative methods. While complete in their coverage, the concise presentation may not be appropriate for those new to the field.

The SPIE Field Guides are intended to be living documents. The modular page-based presentation format allows them to be updated and expanded. We are interested in your suggestions for new Field Guide topics as well as what material should be added to an individual volume to make these Field Guides more useful to you. Please contact us at fieldguides@SPIE.org.

John E. Greivenkamp, Series Editor

College of Optical Sciences

The University of Arizona

The Field Guide Series

Field Guide to Astronomical Instrumentation

This Field Guide to Astronomical Instrumentation is the one book that the three of us would want to carry with us if we had to single-handedly design an astronomical instrument on a remote mountain top. To keep it concise, it focuses on the ultraviolet to infrared wavelength range. The Field Guide is not intended to serve as a textbook, but as a handy desktop reference to be found in the labs and offices of instrument builders.

This book contains information on a wide range of topics, from fundamental physics to project management, and from technical concepts to material properties. Only the most important concepts and equations are presented here. In many areas, dedicated SPIE Field Guides discuss particular topics in much more detail. While we tried to maintain consistency with other volumes in this series, we wrote this Field Guide in the language that instrumental astronomers use, which might sometimes look strange to people working in other areas.

A Field Guide that strives to cover such a wide variety of topics will naturally overlook some potentially relevant topics. We look forward to suggestions from our readers on how to improve this Field Guide for its next edition.

Last but not least, we greatly appreciate the continuous support of our families in this endeavor.

Christoph U. Keller

Leiden Observatory, Leiden University, The Netherlands

Ramon Navarro

NOVA Optical & Infrared Instrumentation Division at ASTRON, The Netherlands

Bernhard R. Brandl

Leiden Observatory, Leiden University, The Netherlands

Table of Contents

Glossary of Symbols and Acronyms xi

General Optics 1

Refraction, Reflection, and Transmission 1

Polarization 2

Brewster Angle and Total Internal Reflection 3

Images, Pupils, and Beams 4

Aberrations 5

Diffraction 6

Point-Spread Function 7

Modulation Transfer Function 8

Spectral Transfer Function 9

Optical Elements 10

Windows 10

Lenses 11

Mirrors 12

Filters 13

Colored Glass Filters 14

Interference Filters 15

Coatings 16

Astronomical Bandpass Filters 17

Prisms 18

Gratings 19

Polarizers 20

Crystal Polarizers 21

Waveplates 22

Optical Fibers 23

Detectors 24

Detector Overview 24

Intrinsic Photoconductors 25

CCD and CMOS Detectors 26

Extrinsic and Stressed Photoconductors 27

BIB Detectors and (Avalanche) Photodiodes 28

Bolometers 29

Coherent (Heterodyne) Detectors 30

CCD and CMOS Readouts 31

Infrared Array Readouts 32

Detector Noise and Artifacts 33

Detector Radiation Effects in Space 34

Detector Flat Fielding 35

Telescopes and Imagers 36

Telescopes 36

Correctors and Wide-Field Imagers 37

Focal Reducers 38

Reimaging Optics 39

High-Resolution Imagers 40

Spectrographs 41

Spectrograph Overview 41

Single-Slit Spectrometer 42

Echelle Spectrometers 43

Slitless Spectrometers 44

Fabry–Pérot Interferometer 45

Fourier Transform Spectrometer 46

Integral Field Spectrometer 47

Multi-object Spectrometer 48

OH-Suppression Spectrographs 49

Spectral Data Analysis 50

Polarimeters 51

Rotating Waveplate Polarimeters 51

Liquid Crystal Polarimeters 52

Spectral Modulation Polarimeters 53

Interferometers 54

Interferometer Principle and Angular Resolution 54

Delay Lines 55

Beam Combiners 56

Fringe Visibility 57

Fringe Tracking and Closure Phase 58

Aperture Synthesis and (u, v) Plane 59

Field of View and Sensitivity 60

Image Processing 61

Coronagraphs 62

Focal-Plane Coronagraphs 62

Pupil-Plane Coronagraphs 63

Space Coronagraphs 64

Adaptive Optics 65

Adaptive Optics 65

Atmospheric Turbulence: Seeing 66

Wavefront Sensors 67

Deformable Mirrors 68

Adaptive Optics Control 69

Laser Guide Stars 70

Operation Modes 71

Optical Design 72

Optical Design Principles 72

Design Approach 73

Ray Tracing 74

Optimization 75

Tolerance Analysis 76

Stray Light Control and Baffles 77

Optomechanics 78

Packaging 78

Optics Mounts 79

Mechanisms 80

Actuators and Motors 81

Sensors 82

Mechanical Engineering for Space 83

Vacuum and Cryogenics 84

Dewars 84

Cooling Methods 85

Thermal Models 86

Thermal Effects in Space 87

Software and Electronics 88

Control 88

Instrument Control System 89

Data Handling 90

Data Transfer from Space 91

Data Analysis Overview 92

Electronics: Cabling 93

Shielding 94

Systems Engineering 95

Systems Engineering: Requirements Definition 95

Block Diagrams 96

Interface Control 97

Error Budgets 98

Noise and its Distribution 99

Signal-to-Noise Ratio 100

Instrument Sensitivity and Integration Time 101

Signal Sampling 102

Project Management 103

Technology Development 104

Risk Management 105

Quality Management 106

Manufacturing, Assembly, Integration, and Testing 107

Optics Manufacturing 107

Optics Testing 108

Alignment 109

Instrument Commissioning 110

Operations and Maintenance 111

Appendices 112

Optical Material Properties 112

Mirror Substrate Material Properties 113

Mechanical Material Properties 114

Material Selection 115

ISO 10110 Optical Drawing Standard 116

ECSS 117

Equation Summary 118

Bibliography 125

Index 127