Radio Telescope Reflectors - Historical Development of Design and Construction

Preface

Contents

Chapter 1: Introduction

Chapter 2: Evolution of the Telescope

2.1 Some History

2.1.1 Early Optical Telescope Efforts

2.1.2 Emergence of Electromagnetic (Radio) Waves

2.2 General Characteristics of Optical and Radio Telescopes

2.2.1 Introduction

2.2.2 Types of Telescope Mount and Optics

2.2.3 Alternative Geometrical Configurations

2.3 Technological Challenges for Radio Telescopes

2.4 Basic Specifications of a Reflector Radio Telescope

2.4.1 Reflector Precision

2.4.2 Pointing Precision

2.5 Summary

Addendum: Geometry of Optical Configuration

References

Chapter 3: Birth of Radio Astronomy

3.1 Early History of Radio Telescopes

3.1.1 Jansky´s Bruce Antenna

3.1.2 Reber´s Transit Paraboloidal Reflector

3.1.3 Würzburg Riese Radar Antenna

3.2 The First Large Radio Telescopes

3.2.1 Dwingeloo (NL) and Stockert (BRD) Telescopes

3.2.1.1 Dwingeloo

3.2.1.2 Stockert

3.2.2 A Comment on Accessibility of the Focal Point

3.2.3 Jodrell Bank (UK): Lovell Telescope (76 m)

3.2.4 Parkes (Australia) 64 m Telescope

3.2.5 NRAO (USA): 140-ft and 300-ft Telescopes

3.2.5.1 NRAO 140-ft Equatorial Telescope: An Expensive and Slow Project

3.2.5.2 NRAO 300-ft Transit Telescope: A Cheap and Quick Deal

3.2.6 The 120-ft Haystack Antenna of MIT Lincoln Laboratory

3.3 Conclusion

References

Chapter 4: Structural Design of Reflector Antennas: Homology

4.1 Introduction

4.2 The Design of Homologous Structures

4.3 The Design of a 65-m Homologous mm Telescope

4.4 The Effelsberg 100-m Radio Telescope

4.4.1 The German Proposal for a Giant Radio Telescope

4.4.2 A Comment on the Homologous Behaviour of a Structure

4.4.3 The Industrial Design Proposals

4.4.4 The Final Design and Realisation

4.5 Backup Structure and Deformation Patterns

4.5.1 The Design Approach of the Effelsberg Backup Structure

4.5.2 Interpretation of the Load Cases of the Effelsberg Reflector

4.5.2.1 Zenith Position

4.5.2.2 Horizon Position

4.5.3 Load Case Superposition

4.5.4 The Deformation Behaviour of the Effelsberg Reflector

4.5.5 Performance Limits of the Effelsberg Reflector Principle

4.6 Four-Point Reflector Support

4.6.1 Introduction

4.6.2 The Westerbork Array of 25-m Antennas

4.6.3 The MERLIN Antenna with a Perfect Four-Point Support

4.6.4 The Joined Four-Point Support of the IGN 40-m Telescope

4.7 Conclusion

References

Chapter 5: Emergence of Millimetre-Wavelength Telescopes

5.1 Into mm Wavelengths

5.2 The NRAO 36-ft Antenna

5.3 The IRAM 30-m Telescope (MRT)

5.3.1 Introduction: Performance Specification

5.3.2 The Design Selection

5.3.3 The Structural Concept of the MRT

5.3.4 The Deformation Behaviour of the MRT

5.3.4.1 Load Case in Zenith Position

5.3.4.2 Load Case in Horizon Position

5.3.4.3 The Deformation Behaviour of the Final Improved Design

5.3.5 Overall Surface Error of the Actual Telescope

5.3.6 Thermal Effects and Their Control

5.3.7 Conclusion

5.4 The Large Millimeter Telescope

5.4.1 Conceptual Design Phase

5.4.2 Towards a Final LMT Design

5.4.3 The Final Design of the LMT/GTM

5.4.4 Short Review of Surface Panel Technology

5.4.5 The Isostatic Reflector Segments of the LMT

5.4.6 Flexible Body Control (FBC)

5.4.7 Concluding Remark on the LMT/GTM

5.5 The Nobeyama 45-m Millimeter Telescope

5.6 Conclusion

Addendum: Thermal Effects and Their Control

References

Chapter 6: Submillimetre-Wavelength Telescopes

6.1 Introduction

6.2 Leighton Dish and CSO Telescope

6.3 CFRP Telescopes: IRAM 15-m and HHT

6.3.1 The IRAM Interferometer Antennas

6.3.2 The Heinrich Hertz (Submillimeter) Telescope (HHT)

6.4 Atacama Large Millimeter Array (ALMA) Antennas

6.4.1 Introduction

6.4.2 Test Program and Performance of the ALMA Prototype Antennas

6.4.3 Remark on the Circular BUS/ELC Interface Concept

6.4.4 Comparison of the Designs from AEM/EIE and Vertex

6.4.4.1 Comparison of Structural Design

6.4.4.2 Weight

6.4.4.3 Deformation Behaviour

6.4.4.4 Interpretation of the Astigmatism from Basic Structural Mechanics

6.4.4.5 Comparison of the Bearing and Drive Systems

6.4.4.6 Dynamic Behaviour, Structural Resonance Frequencies

6.4.5 Conclusion

References

Chapter 7: Alternative Reflector Geometries

7.1 Telescopes with Fixed Main Reflectors

7.2 The Giant Metrewave Radio Telescope (GMRT) in India

7.3 Large Horn Antennas

7.4 Offset Reflector Antennas

7.4.1 Introduction

7.4.2 Allen Telescope Array (ATA)

7.4.3 MeerKAT and Square Kilometre Array (SKA)

7.4.4 Green Bank Telescope (GBT)

Addendum: Remarks on Wheel-On-Track Systems

References

Chapter 8: Electromagnetic Aspects of the Reflector Antenna

8.1 Introduction

8.2 Radiation Pattern of a Circular Aperture

8.3 Major Parameters of the Reflector Antenna

8.4 Influence of Imperfections on Performance

8.4.1 Illumination, Spillover and Polarisation Efficiency

8.4.2 Radiation Efficiency

8.4.3 Small-Scale Surface Error (Scattering) Efficiency

8.4.4 Large-Scale Deformation: Representation by Zernike Polynomials

8.4.5 Blocking Efficiency

8.4.6 Lateral and Axial Defocus: Gain Loss

8.4.7 Beam Deviation Factor (BDF)

8.4.8 Conclusion

8.5 Measuring Antenna Parameters with Cosmic Sources

8.5.1 Antenna Gain and Beam Pattern

8.5.2 Antenna Pointing

8.6 Radio Holographic Measurement of Reflector Profile

8.7 Progress in Electromagnetic Design

8.7.1 Historical Introduction

8.7.2 Radio Astronomy and Communication Approaches Differ

8.7.3 Exploiting the Focal Plane

8.7.3.1 Multi-feed System with Independent Pixels

8.7.3.2 Phased-Array Feeds (PAF)

8.8 Conclusion

Addendum: Aberrations and Zernike Polynomials

References

Chapter 9: Concluding Review and a Dialogue on Management Aspects

9.1 Concluding Review

9.2 A Dialogue on Management Aspects

9.2.1 Customer and Contractor

9.2.2 Project Management and System Engineering

9.2.3 Technological Aspects

9.2.4 Industrialisation Aspects, Costs

9.2.5 Manufacturing in Foreign Countries

9.2.6 Product Delivery, Commissioning

Acronyms and Abbreviations

Glossary

Name Index

Subject Index