Modern Astrometry

Book excerpt: An introduction to practical astrometry, dealing with the determination of positions, motions, distances and dimensions of celestial bodies - ranging from quasars to artificial satellites. The main part is devoted to the description of optical instruments together with the atmospheric effects on observations. Although classical astrometric methods (photography, meridian circles, astrolabes) are described, the emphasis is firmly laid on new, more precise techniques such as CCD, optical and radio interferometry, and space astrometry. The whole is rounded off by a brief summary of data treatment and of the main phenomena in positional astronomy.