A Summary and Further Studies

Abstract

Radio telescopes are built for observations frommeter to sub-millimeter wavelengths (Table 1.1). The steerable telescopes have a parabolic reflector of 10–100–m diameter and the optics can be designed for observations in primary focus, Cassegrainian focus, or Gregory focus (Sect. 2.1). The telescopes have a support, that is, a pedestal, an alidade, or a fork; a reflector backup structure and panels; and a quadripod with subreflector (Fig. 1.1, Chap. 2). The construction material is steel, aluminium, low thermal expansion reinforced carbon fiber plastic (CFRP), and invar, and concrete for the pedestal and foundation (Sect. 2.4). The design of a telescope is based on a finite element analysis, a flexible body analysis (which considers the telescope, the drives, and the control system as one dynamical unit (Kärcher 2006; Gawronski 2007)), and static and/or dynamic thermal model calculations (Sects. 11.2 and 11.3). The backup structure can be a homologous design (Sect. 2.4.2). The technical efforts applied in the control of temperature (and wind) induced deformations must be seen in the context of the envisaged sensitivity and directivity, and also in the context of the time spent in focus and pointing measurements.