Thermal design and thermal behaviour of radio telescopes and their enclosures

Radio telescopes as well as communication antennas operate under the influence of gravity, temperature and wind. Among those, temperature influences may degrade the performance of a radio telescope through transient changes of the focus, pointing, path length and sensitivity, often in an unpredictable way. Thermal Design and Thermal Behaviour of Radio Telescopes and their Enclosures reviews the design and construction principles of radio telescopes in view of thermal aspects and heat transfer with the variable thermal environment; it explains supporting thermal model calculations and the application and efficiency of thermal protection and temperature control; it presents many measurements illustrating the thermal behaviour of telescopes in the environment of their observatory sites. The book benefits scientists and radio/communication engineers, telescope designers and construction firms as well as telescope operators, observatory staff, but also the observing astronomer who is directly confrontedwith the thermal behaviour of a telescope." First English language book presenting and reviewing the subject. The basic physics of heat transfer is compiled Explains models for numerical analysis of the thermal state of large mechanical structures. It demonstrates, with examples, the confidence and the precision obtained in calculating, and predicting, the thermal behavior of radio telescopes The thermal tolerances of a telescope structure are explained, and related to the radio performance of a telescope Contains many temperature measurements that illustrate the thermal behavior and achieved thermal stability The climatic parameters of low and high altitude observatory sites defining the thermal environment are summarized The examples provide guidelines for temperature manipulation, thermal protection, and engineering concepts for future telescopes INDICE: Foreword.- Preface.- 1 Radio Astronomy and Radio Telescopes.- 2 Radio Telescope Constructions in View of Thermal Aspects.- 3 Telescope Enclosures.- 4 The Variable Thermal Environment.- 5 Calculation of Solar Illumination.-6 Temperature Measurements and FEM Thermal Deformation Calculations.- 7 Heat Transfer.- 8 Radiative Coupling towards Sky and Ground (External View Factor).- 9 Measured Thermal Behaviour of Radio Telescopes.- 10 Measured Thermal Behaviour of Enclosures.- 11 Thermal Model Calculations.- 12 Beam Formation and Beam Degradation.- 13 Thermal Tolerances.- 14 Optical Telescopes and Enclosures.-15 A Summary and Further Studies.- A Units and Fundamental Constants.- B Average Value, Root–Mean–Square Value (rms).- C Pointing Model.- D Zernike Polynomials.- E Literature.- F Picture and Graphic Credits.

• ISBN: 978-3-642-03866-2
• Editorial: Springer
• Encuadernacion: Cartoné
• Páginas: 420
• Fecha Publicación: 01/11/2009
• Nº Volúmenes: 1
• Idioma: Inglés