This book is an up-to-date and comprehensive account of current observational techniques with particular emphasis on optical astronomy. Dr Walker, a world expert in astronomical instrumentation, has written a complete survey of the basic electromagnetic spectrum. The author discusses the types and sources of stellar electromagnetic radiation and the range of telescopes that are used to observe them. Topics covered include the construction of sensitive low-noise detectors, preservation of image quality, and the limits to measurement precision. The book is particularly timely because...