The papers presented in this volume explain to nonspecialists the state of the art in key areas of radio science, including the optical techniques now playing an important role in electronics and communications. These reviews are readable, authoritative, and up-to-date. They are authored by a panel of distinguished, internationally recognized experts from East and West, and will be valued both by specialists in other areas desiring access to major advances in the field, and by novices seeking an introduction to the subject.