Original contributions

In view of the large scope of this dissertation it may be useful to outline the main original contributions that are brought into this work.

At a general level this work aims at bringing together and developing concurrently a number of interrelated topics that determine fundamentally the concept and the design of an astronomical observatory. In this sense this work aims at becoming a scientific reference, which the author felt was missing.

Chapter 2 essentially reorders the main existing definitions and notions related to seeing and wind effects on telescopes and provides a common base for their quantification with respect to the telescope performance. Chapter 3 is a critical appraisal of the problems arising in the existing observatories, which leads to define more concretely the needs for new developments.

Chapter 4 presents the results and the evaluation of several aerodynamic measurements both at full scale and in the wind tunnel. While the test methods used are quite established, they had not before been applied in that context. The accurate quantification of the mechanical turbulence caused on a telescope by several different types of enclosure is here published for the first time. Also the analysis of the optical effects of wind buffeting on a large mirror represents an original contribution to the further development of advanced active and adaptive optics. While some parts of this work benefited from the collaboration of a large team at ESO (see the authors' list of [Noethe 92]), the definition of the wind engineering aspects as well as the final evaluation and conclusions presented here are by the author.

Chapter 5 includes mostly original and unpublished material. We will cite here the parametric estimates for the seeing in domes and the one caused by the telescope's secondary mirror. The largest set of seeing data from one of the world best observatories is analyzed statistically for the first time. The core of the work lies then in the study of mirror seeing, identified as the likely most important effect in a modern telescope: an original physical description of the phenomenon is presented as well as the analysis and comparison of various experiments, leading to engineering parameterizations reliably applicable to an actual telescope design.

Chapter 6 draws the main consequences of the scientific results on the engineering of astronomical observatories. The systems engineering statistical approach presented here takes its ground stones from the parameterizations obtained in this work and follows from the author's considerations on the complexity and interrelationship of all topics studied.

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Figure: Optical schematics of an astronomical telescope