"Modern Astrometry" is a comprehensive and updated technical literature that deals with the latest advancements in astrometry. In the second edition of the book, the information has been revised to reflect the enormous developments of recent years. Significant changes include the publication of the Hipparcos and Tycho catalogs, as well as the introduction of CCD astrometry. The book also addresses the decision of the International Astronomical Union to adopt a new celestial reference system and the advancements in precise time and frequency measurement. These aspects, along with the development of new space missions for astrometry and progress in optical interferometry, are discussed in detail. The historical relevance of traditional instruments such as astrolabes and transit circles is preserved, while new methods and instruments are also introduced. The multitude of new references supplements the original list and provides readers with a comprehensive overview of the current state of astrometry.