Astronomical Telescope Design

Astronomical Telescope Design

Course Code: 031M4015H

Course Name: Astronomical Telescope Design

Credits: 3.0

Level: Undergraduate

Pre-requisites: General Astronomy, Optical Engineering, Mechanical Design, Finite Element Analysis, Precision Transmission Technology

Lecture Time: 9 weeks, 2 sessions/week, 3 hours/session, 54 hours

Instructors: Zhang Haiying, Hu Qiqian, Wang Guomin

Course Description

Astronomical telescopes are important devices that astronomers use to observe stars and explore the mysteries of the universe. The performance of astronomical telescopes directly affects the level of astronomy research. Therefore, how to design an astronomical telescope with excellent performance is very important for astronomy research. This course consists of three parts: basic knowledge of astronomical telescopes, optical telescopes and solar telescopes. The basic knowledge section systematically introduced the development history of telescopes and astronomy, the celestial coordinate system and its transformation, the rack form of the telescope, the wave optics and geometric optics foundation, the engineering structural mechanics and the finite element principle; the optical telescope section will introduce the basics of optical telescope design. Mirror support for telescopes, racks and tubes for telescopes, shafting and transmission of telescopes, and pointing and tracking technologies for telescopes; solar telescopes section will introduce solar physics basics and solar observation site selection and instruments, various types of solar telescopes, solar spectrum, monochromatic light, solar field velocity field observation equipment, and space solar observation equipment and solar radio telescope.

Topics and Schedule

Part Ⅰ Basic knowledge of astronomical telescope (18 hours)

  1. 1.Telescope and Astronomy (3 hours)
  2. 1.Importance of astronomy, the relationship between astronomy and astronomical instruments, the category of astronomical instruments.
  3. 2.The astrometry and instruments in ancient time
  4. 3.The classic methods of astrometry, nonuniformity of the earth movement, time and latitude measuring instruments, modern measurement for celestial body
  5. 4.The high accurate astrometry by radio telescope interferometer
  6. 5.Invention of telescope, earlier refractive telescopes
  7. 6.Invention of reflective telescopes
  8. 7.Development in science and technology in modern time improved development in telescope technology
  9. 8.Classic large telescopes before the 1990s
  10. 9.8-10 m modern telescopes with new technology
  11. 10.Giant ground-based telescopes in manufacturing, space telescopes
    1. 2.Celestial coordinate system and its tranformation (2 hours)
  12. 1.Alt-azimuth coordinate system, equatorial coordinate system and horizontal coordinate system
  13. 2.Formulas transformation for celestial coordinate systems
    1. 3.The Telescope Mountings (2 hours)
  14. 1.Function and constitute of the telescope mountings
  15. 2.Types and characteristic of the telescope mountings
  16. 3.Special telescope mountings, the heliostat and the coelostat
  17. 4.The image-field rotation of telescopes
    1. 4.Basic knowledge on wave optics (5 hours)
  18. 1.Research objects in wave optics, the relevant mathematics formula, Concept about the space frequency and complex amplify, wave optics applications in telescope design
  19. 2.Theory of diffraction, Fresnel diffraction and Fraunhofer diffraction, imaging principle of telescopes
  20. 3.Point Spread Function, PSF for the typical pupil functions
  21. 4.Object-image Formulas based on the space frequency theory
  22. 5.Wave optics applications in the astronomy observation, theoretical resolving power of telescopes, focal depth, Criterion of perfect optics systems, evaluate of image quality of optics systems
  23. 6.Principle of astronomical interference, double pupil interference of mono-mirror, modern stellar interferometers
    1. 5.Basic knowledge on the geometry optics (3 hours)
  24. 1.Basic theory of the geometry optics, the refraction law and the reflection law
  25. 2.Field of view and aperture, entrance pupil and exit pupil, Stop and vignetting, control for the principal rays
  26. 3.Formulas of close-axis spherical system, object-image formulas, amplification
  27. 4.Thin lenses and reflection spherical mirrors
  28. 5.Ideal optic systems, focal length and principal plane, main formulas
  29. 6.Typical optics of astronomy telescopes, refraction system and reflection system
    1. 6.Engineering Structural Mechanics and the Principle about Finite Element (3 hours)
  30. 1.The application of engineering structural mechanics in astronomical telescope design
  31. 2.The formulas of material mechanics:strength, shear,torque,bending
  32. 3.The basic knowledge and formulas of elastic mechanics
  33. 4.The basic knowledge of finite element, finite element method for rods and plane stress
  34. 5.The relationship between structural deformation and telescope imaging
  35. 6.Some mechanical problems in part design

Part Ⅱ Optical telescope (18 hours)

  1. 7.General introduction of optical telescope (3 hours)
  2. 1.Introduction on optical telescope
  3. 2.Design and development process of optical telescope
  4. 3.Site and dome
  5. 4.Telescope installation on site and performance testing
    1. 8.Mirror support technology (3 hours)
  6. 1.Primary mirror support
  7. 2.Secondary mirror support
  8. 3.Third mirror support
  9. 4.Small mirrors and Lens mount
  10. 5.Alignment between mirrors and adjust method
  11. 6.Methods to test the support performance
    1. 9.Telescope mount and tube design (3 hours)
  12. 1.Equatorial mount
  13. 2.Altitude-azimuth mount
  14. 3.Altitude-altitude mount
  15. 4.Other special mounts
  16. 5.Tube design (mirror cell, center section, truss, etc.)
    1. 10.Telescope shaft design and support bearing (3 hours)
  17. 1.Telescope shaft design
  18. 2.Structural mechanics calculation and analysis
  19. 3.Shaft support bearing
  20. 4.Methods to adjust and test the bearing performance
    1. 11.Telescope drive technology (3 hours)
  21. 1.Worm gear drive
  22. 2.Gear drive
  23. 3.Friction drive
  24. 4.Direct drive
    1. 12.Telescope pointing and tracking (3 hours)
  25. 1.Pointing error source and error analysis
  26. 2.Pointing model set up
  27. 3.Control device (motor, encoder, amplifier, etc.)
  28. 4.Telescope tracking control

Part Ⅲ Solar telescope (18 hours)

  1. 13.Solar observation and site selection (2 hours)
  2. 1.The significance of solar study
  3. 2.Solar physics fundamentals
  4. 3.The effect of Earth's atmosphere on solar observations
  5. 4.Solar observation site selection and instrumentation
    1. 14.Imaging system of solar telescope (4 hours)
  6. 1.Chromosphere telescope
  7. 2.Coelostat and Heliostats
  8. 3.Sunseeker
  9. 4.Coronagraph
  10. 5.Multi-channel Solar Telescope
  11. 6.New Vacuum Solar Telescope
  12. 7.Pre-study on Chinese Giant Solar Telescope
    1. 15.Instruments for solar spectrum observation (3 hours)
  13. 1.Characteristics of the solar spectrum
  14. 2.Grating spectrometer
  15. 3.Solar monochromator
  16. 4.Two-dimensional spectrometer
  17. 5.Fourier Transform Spectrometer
  18. 6.Integral Field Unit Spectrometer
    1. 16.Solar monochromatic light observation instrument (3 hours)
  19. 1.Monochromatic light observation
  20. 2.Solar monochromator
  21. 3.Birefringent filter
  22. 4.Interference filter
  23. 5.Solid Michelson Interferometer
  24. 6.Multi-channel filter
    1. 17.Measurement of solar magnetic field and velocity field (4 hours)
  25. 1.The significance of solar magnetic field measurement
  26. 2.The development of solar magnetic field measurement
  27. 3.The principle of solar magnetic field measurement
  28. 4.The observation equipment for solar velocity field
    1. 18.Space Solar Observations and Solar Radio Observations (2 hours)
  29. 1.Development history of space solar observations
  30. 2.Balloon-borne solar telescope
  31. 3.The program of space solar observation
  32. 4.The significance of solar radio observations
  33. 5.Chinese Spectral Radioheliograph

Grading

The grades include check-in times, final examination and assignments of weekly homework

References

[1] Pierre Y. Bely, The Design and Construction of Large Optical Telescopes, New York: Springer, 2003

[2] Hu Qiqian, Yao Zhengqiu, Astronomical Telescope Design, China Science & Technology Press, 2013 (Chinese version)

[3] Hu Qiqian, Telescope technology and astronomical surveying, Southeast University Press, 2014 (Chinese version)

[4] Cheng Jingquan, Principles of astronomical telescope design, China Science & Technology Press, 2003 (Chinese version)

[5] Lin Yuanzhang, Introduction to solar physics, Science Press, 2000 (Chinese version)

[6] Huang Youran, et al. Observational astrophysics, Science Press, 1987 (Chinese version)