In the monograph of famous scientists from Germany, a detailed description of modern tools and methods of radio astronomy is given. A wide range of issues from the foundations of electrodynamics to the creation of modern telescopes and receivers is considered. The book is intended for scientists and engineers working both in radio astronomy and in related sciences - radio physics, radio engineering, antenna, radiometric and communication technology. The presence of a large number of interesting and practical tasks makes this book a ready-made textbook for senior students of relevant specialties and graduate students.