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by Trueblood and Genet
6 by 9 inches, 562 pages, hardbound, 183 figures,
$29.95
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About this book:

Computer control has spread to so many industries that many system components, such as motor controller boards for the PC-clone, Macintosh, and UNIX workstation are now available commercially.

In the previous edition of this book, the authors included several circuit schematic diagrams for custom electronics to perform functions that can now be performed by off-the-shelf circuitry. Many of these boards are affordable by amateurs and can save a great deal of time in developing a system. In this book, you will see fewer electronic schematics and more examples of how to use off-the-shelf boards and subsystems to configure your control system quickly.

This book still fills a gap in the books that are available on using personal computers in astronomical applications. Most of the other books stress computing that can be done at the leisure of both the hobbyist and the computer, and computing that uses only the basic computer and standard peripheral devices (disks, printers, etc.) as they come from the computer store. Image processing and orbit computing are examples of this type of computing.

This book is primarily concerned with how to connect a non-standard computer peripheral device (a telescope) to a computer and how to program the computer to perform time-critical computations. This is only one example of the more general problem of real-time control, so if viewed in this larger context, this book should find an audience among those interested in any real-time control application, such as robotics.

From the Reviewers

Telescope Control contains a wealth of information for the reader with some knowledge of electronics and software who wants to build a computerised telescope, and I can throuroughly recommend it.
                                                                                              —Journal of the British Astronomical Association

Table of Contents
Chapter 1 Introduction
   1.1 Overview
   1.2 Organization of Topics

Part I Why and How to Computerize a Telescope

Chapter 2 Why Control Telescopes With Computers?
   2.1 Reasons for Computerized Telescope Control
   2.2 Cost/Benefit Reasons
   2.3 Modern Observing Methods
Chapter 3 Modern Systems Engineering
   3.1 The Project Life Cycle
   3.2 Defining Your System's Requirements
      3.2.1 Portability
      3.2.2 Setup Time
      3.2.3 Optics
      3.2.4 Telescope Pointing Accuracy
      3.2.5 Telescope Pointing Time
      3.2.6 Long Term Tracking Accuracy
      3.2.7 Short Term Tracking Accuracy
      3.2.8 Data Input and Control Devices
      3.2.9 Computer Environment
      3.2.10 Commands
      3.2.11 Extraneous Light Control
   3.3 Designing Your System
      3.3.1 Method of Transport
      3.3.2 Telescope Mount Type
      3.3.3 Optical System
      3.3.4 Drive Design Approach
      3.3.5 Control System Approach
      3.3.6 Computational Requirements
      3.3.7 Computer Hardware and Software
         3.3.7.1 Processor Speed
         3.3.7.2 Arithmetic Hardware
         3.3.7.3 Interrupt Hardware
         3.3.7.4 Standard Bus Structure
         3.3.7.5 Development Environment
         3.3.7.6 Operating System

Part II Telescope Control System Design Considerations

Chapter 4 An Introduction to Control Theory
   4.1 Control Options
   4.2 The Role of Position Feedback
   4.3 Equation of Motion
   4.4 The Role of Velocity Feedback
   4.5 Matching the Telescope and the Control System
Chapter 5 Systematic Errors I — Astronomical Corrections
   5.1 Precession
      5.1.1 The Physical Basis of Precession
      5.1.2 Magnitude of the Precession Corrections
      5.1.3 Computing General Precession
   5.2 Nutation
      5.2.1 The Physical Basis of Nutation
      5.2.2 Magnitude of the Nutation Corrections
      5.2.3 Computing Nutation
   5.3 Polar Motion
   5.4 Sidereal Time
      5.4.1 About Time
      5.4.2 Magnitude of Time Corrections
      5.4.3 Computing Sidereal Time
   5.5 Aberration
      5.5.1 The Physical Basis of Aberration
      5.5.2 Magnitude of Stellar Aberration Corrections
      5.5.3 Computing Annual Aberration
      5.5.4 Computing Diurnal Aberration
      5.5.5 General Relativistic Effects
   5.6 Parallax
      5.6.1 The Physical Basis of Parallax
      5.6.2 Magnitude of Parallax Corrections
      5.6.3 Computing Stellar Parallax
      5.6.4 Computing Solar or Planetary Parallax
   5.7 Refraction
      5.7.1 The Physical Basis of Refraction
      5.7.2 Magnitude of Refraction Corrections
      5.7.3 Computing Refraction
      5.7.4 Parallactic Refraction
   5.8 Orbital Motion
   5.9 Proper Motion
   5.10 Reduction from Mean to Topocentric Place
   5.11 Changes in the 1984 Ephemerides
Chapter 6 Systematic Errors II — Mechanical Corrections
   6.1 Telescope Mount Designs
   6.2 Telescope Pointing Corrections—Equatorial Mount
      6.2.1 Zero Offset
      6.2.2 Polar Axis Alignment
      6.2.3 Driving Rates
   6.3 Telescope Pointing Corrections—Alt-Az Mount
      6.3.1 Zero Offset
      6.3.2 Azimuth Axis Alignment
      6.3.3 Equatorial to Alt-Az Conversion
         6.3.3.1 Conversion Equations
         6.3.3.2 Driving Rates
         6.3.3.3 Field Rotation Corrections
   6.4 Telescope Pointing Corrections—Alt-Alt Mount
      6.4.1 Zero Offset
      6.4.2 North-South Axis Alignment
      6.4.3 Equatorial to Alt-Alt Conversion
         6.4.3.1 Conversion Equations
         6.4.3.2 Driving Rates
         6.4.3.3 Field Rotation Corrections
   6.5 Intrinsic Telescope Corrections
      6.5.1 Non-Perpendicular Axis Alignment
      6.5.2 Non-Alignment of Mechanical and Optical Axes
      6.5.3 Tube Flexure
      6.5.4 Mount Flexure
      6.5.5 Servo Lag Errors
      6.5.6 Position Encoder Errors
      6.5.7 Gearing Errors
      6.5.8 Bearing Errors
      6.5.9 Drive Train Torsion Errors
   6.6 Reducing the Effects of Systematic Errors
      6.6.1 Mechanical Adjustments
      6.6.2 Compensating for Mechanical Behavior in Software
Chapter 7 Practical Design Considerations
   7.1 Operator Convenience
   7.2 Hardware/Software Tradeoffs
   7.3 Single Board Computers and Buses
   7.4 Hardware Approaches
   7.5 Interface Software
   7.6 Adaptability
   7.7 Reliability
   7.8 Maintainability
   7.9 Safety
   7.10 Conclusions

Part III Telescope Control System Components

Chapter 8 Motors and Motor Controllers
   8.1 A Standard Telescope Problem
   8.2 Large DC Torque Motors
   8.3 Servo Motors
   8.4 Servo Motor Controllers and Computer Interfaces
   8.5 Stepper Motors
   8.6 Stepper Motor Controllers and Computer Interfaces
Chapter 9 Sensors
   9.1 Precision Potentiometers
   9.2 Variable Reluctance Transformers
   9.3 Resolvers
   9.4 Synchros
   9.5 Inductosyns
   9.6 Rotary Differential Capacitors
   9.7 Optical Shaft Angle Encoders
   9.8 Other Encoder Types
   9.9 Time Code Receivers
   9.10 Other Useful Sensors
Chapter 10 The Operator Interface
   10.1 Types of Operator Interfaces
   10.2 Characteristics of a Good Operator Interface
   10.3 Design of Graphical User Interfaces
Chapter 11 Computers and System Software
   11.1 Characteristics of Real-Time Command and Control
   11.2 Selecting Computer Hardware
   11.3 Selecting the Operating System
   11.4 Selecting the Development Environment

Part IV Examples of Telescope Control Systems

Chapter 12 The Phoenix  IV Telescope Control System

   12.1 History of the Phoenix IV Telescope
   12.2 Drive Train
      12.2.1 Electronic
      12.2.2 Software
      12.2.3 Development History
   12.3 A Platform-Independent Approach
      12.3.1 The Nyden Motion Controller
12.3.1 The Nyden Motion Controller
12.3.2 Bi-Polar Chopper Stepper Translators
12.3.3 Analog Joystick
12.3.4 Software
Chapter 13 The WMO Telescope Control System
   13.1 The WMO Observing Program
   13.2 System Operational Environment
   13.3 System Performance Requirements
      13.3.1 Portability
      13.3.2 Setup Time
      13.3.3 Optics
      13.3.4 Telescope Pointing Accuracy
      13.3.5 Telescope Pointing Time
      13.3.6 Long Term Tracking Accuracy
      13.3.7 Short Term Tracking Accuracy
      13.3.8 Data Input and Control Device
      13.3.9 Computer Environment
      13.3.10 Commands
      13.3.11 Extraneous Light Control
   13.4 Overall System Design and Evolution
      13.4.1 Method of Transport
      13.4.2 Telescope Mount Type
      13.4.3 Optical System
      13.4.4 Drive Design Approach
      13.4.5 Control System Approach
      13.4.6 Top Level System Design
   13.5 Position Encoder Calibration
   13.6 Computational Requirements
      13.6.1 Topocentric Place Correction
         13.6.1.1 General Precession
         13.6.1.2 Nutation
         13.6.1.3 Aberration
         13.6.1.4 Parallax
         13.6.1.5 Refraction
         13.6.1.6 Orbital Motion
         13.6.1.7 Proper Motion
      13.6.2 Mechanical Corrections
         13.6.2.1 Conversion of the Encoder Reading
         13.6.2.2 Zero Offset
         13.6.2.3 Polar Axis Alignment
         13.6.2.4 Azimuth Axis Alignment
         13.6.2.5 Equatorial to Alt-Az Conversion
         13.6.2.6 Nonperpendicular Axis Alignment
         13.6.2.7 Collimation Errors
         13.6.2.8 Tube Flexure
         13.6.2.9 Mount Flexure
         13.6.2.10 Servo Lag Error
      13.6.3 Processor Loading Calculations
   13.7 Selection of the Development and Control System Environments
   13.8 System Development and Evolution
   13.9 Detailed Servo Design
   13.10 Drive Train Design
      13.10.1 Drive Train Mechanical Design
      13.10.2 Motor and Motor Gearing Selection
      13.10.3 Motor Controller Computer Interface Selection
      13.10.4 Position Encoder Selection
      13.10.5 Position Encoder Computer Interface Selection
   13.11 Computer System Hardware
      13.11.1 Control Computer
      13.11.2 Operator Interface
      13.11.3 Telescope Drive
      13.11.4 High Speed Photometer
   13.12 Software Design
      13.12.1 Operational Considerations
      13.12.2 Top-Level Software Design
   13.13 Assessment of System Performance Reqirements
      13.13.1 Portability
      13.13.2 Setup Time
      13.13.3 Optics
      13.13.4 Telescope Pointing Accuracy
      13.13.5 Telescope Pointing Time
      13.13.6 Long Term Tracking Accuracy
      13.13.7 Short Term Tracking Accuracy
      13.13.8 Data Input and Control Device
      13.13.9 Computer Environment
      13.13.10 Commands
      13.13.11 Extraneous Light Control
Chapter 14 Professional and Commercial Telescope Control Systems
   14.1 The Keck 10-m Telescope Control System
   14.2 ACE PC-Based Control System
   14.3 AB Engineering
   14.4 COMSOFT PC-TCS
   14.5 Soft-Tec Systems
   14.6 EPICS
   14.7 Gemini 8-meter Telescopes Control System
   14.8 Indiana University Control System
   14.9 Quadrant Systems

Part V Robotic Telescope Control

Chapter 15 Automatic Photoelectric Telescopes (APTs)
   15.1 Robotic Telescopes
   15.2 Automatic Photoelectric Telescopes (APTs)
   15.3 Astronomical Considerations
   15.4 The Telescope
   15.5 Mount and Drives
   15.6 Control System
   15.7 Background of the APT Project
Chapter 16 Basic APT Control Hardware
   16.1 Introduction
   16.2 Telescope Mount and Drive
   16.3 Control System Hardware
      16.3.1 System Block Diagram
      16.3.2 PT69 Computer
      16.3.3 Telescope Control Board
      16.3.4 Stepper Drivers
      16.3.5 Hand Paddle
Chapter 17 Basic APT Control Software
   17.1 Introduction
   17.2 Elementary Software
   17.3 APT Software Functions and Subprograms
      17.3.1 MAIN
      17.3.2 Build Rise/Set Time Table
      17.3.3 Open Output File
      17.3.4 Initialize Telescope
      17.3.5 Determine Which Group to Observe
      17.3.6 Check Moon
      17.3.7 Move to Group
      17.3.8 Hunt and Lock
      17.3.9 Make Photoelectric Measurements
      17.3.10 Store Measurements
      17.3.11 Evaluate Group Data
   17.4 APT Supporting Procedures and Files
      17.4.1 COEFFICIENTS
      17.4.2 DIGITAL
      17.4.3 HELIO
      17.4.4 HUNT
      17.4.5 LOCK
      7.4.6 LUNAR
      17.4.7 MEAS
      17.4.8 MOVE
      17.4.9 PRECESS
      17.4.10 PTLCK
      17.4.11 RAMP
      17.4.12 SHOCO
      17.4.13 SOLAR
      17.4.14 STARFILE
      17.4.15 STARTSCOPE
      17.4.16 STOPSCOPE
      17.4.17 SUNANGLE
      17.4.18 THRESH
      17.4.19 TIME
      17.4.20 TRAVEL
      17.4.21 ZENITH
   17.5 Auxiliary Procedures
      17.5.1 BUILDFILE
      17.5.2 DATREAD
      17.5.3 JOY4
      17.5.4 MANCO
      17.5.5 SET
      17.5.6 SHOWTIM
      17.5.7 TILDARK
      17.5.8 TRANSFORM
Chapter 18 Advanced Robotic Telescope Control
   18.1 The Normal Growth of Complexity and Specialization
   18.2 Automatic Telescope Instruction Set (ATIS)
   18.3 Centering and Finding Stars
   18.4 Improved Accuracy and Quality Control
   18.5 Fully Automated CCD Photometry
   18.6 Fully Automated Stellar Spectroscopy
   18.7 Networked Robotic Telescopes
   18.8 AI-Based Operations
   18.9 The Future of Robotic Telescope Control
Appendix A Telescope Control System Costs
Appendix B Manufacturers of Motors and Related Hardware
Appendix C Manufacturers of Position Sensors
Appendix D Manufacturers of PC-Clone Products
Appendix E Manufacturers of Items Related to Telescope Control
Appendix F APT Control Algorithms
   F.1 Introduction
   F.2 Computer Mathematics
   F.3 Modified Julian Date
   F.4 Local Mean Sidereal Time
   F.5 Position of the Sun
   F.6 Position of the Moon
   F.7 Zenith Angle
   F.8 Heliocentric Correction
   F.9 Precession to Current Coordinates
   F.10 Determination of Observability of a Star
Appendix G Automatic Photoelectric Telescope Software
Appendix H Phoenix IV Control Software
Appendix I Calibrating Encoders Using Kalman Filtering
   I.1 Weighted Least Squares
   I.2 Kalman Filter
   I.3 Extended Kalman Filter
Appendix Glossary
Bibliography
Index