A new generation of large, ground-based telescopes are just coming into operation. They will take astronomical research well into the next century. These extremely powerful telescopes demand specially designed instruments and observing techniques. The VII Canary Islands Winter School of Astrophysics gathered together leading experts from around the world to review this technology. Based on the meeting, this timely volume presents eight specially written chapters covering all aspects of telescope instrumentation. This book provides an essential reference for all astronomers who will be the users of these large telescopes. It reviews both the challenges involved in designing successful instrumentation and the questions in astronomy they must address. We are taken from the fundamentals of astronomical imaging, low- and high-resolution spectroscopy, and polarimetry up to the state-of-the-art technology in adaptive optics and laser guide stars, interferometry, image pattern recognition, and optical, near and mid infrared arrays. This timely volume provides an excellent introduction for graduate students and an invaluable reference for researchers using the latest generation of large astronomical telescopes.

A few years ago, a real break-through happened in observational astronomy: the un derstanding of the effect of atmospheric turbulence on the structure of stellar images, and of ways to overcome this dramatic degradation. This opened a route to diffraction-limited observations with large telescopes in the optical domain. Soon, the first applications of this new technique led to some outstanding astrophysical results, both at visible and infrared wavelengths. Yet, the potential of interferometric observations is not fully foreseeable as the first long-baseline arrays of large optical telescopes are being built or cOIIllnissioned right now. In this respect a comparison with the evolution of radio-astronomy is tempting. From a situation where, in spite of the construction of giant antennas, low angular resolution was prevailing, the introduction of long baseline and very long baseline interferometry and the rapid mastering of sophisticated image reconstruction techniques, have brought on a nearly routine basis high dynamic range images with milliarcseconds resolution. This, of course, has completely changed our views of the radio sky.